Styleworts under the microscope: a taxonomic account of Levenhookia (Stylidiaceae)

Abstract A taxonomic revision of the Australian endemic genus Levenhookia R.Br. (Stylidiaceae) recognises 12 species, of which L. aestiva Wege, sp. nov. from south-western Australia is newly described. Levenhookia preissii (Sond.) F.Muell. is lectotypified and recircumscribed as a Swan Coastal Plain endemic, resulting in its addition to the Threatened and Priority Flora List for Western Australia. Lectotypes are also selected for L. dubia Sond., L. leptantha Benth., L. sonderi (F.Muell.) F.Muell. and L. stipitata (Benth.) F.Muell. ex Benth. Verification of herbarium records has expanded the known distribution of L. murfetii Lowrie & Conran and L. pulcherrima Carlquist and has confirmed the widespread distribution of L. dubia across southern Australia including Tasmania, where it is currently listed as extinct-surveys based on information gleaned from historical collections may lead to its rediscovery in this State. Descriptions, distribution maps and photographs for all species are provided along with a key to species.


Introduction
The Stylewort genus Levenhookia R.Br. (Stylidiaceae: Asterales) is endemic to the southern temperate and arid zones of Australia and comprises 12 mostly diminutive annual species (Fig. 1) with delicate and intricate flowers that are best observed under magnification. The genus was established by Robert Brown (1810) who aptly named it for Antony van Leeuwenhoek (1632-1723), a Dutch shopkeeper and celebrated microscopist who crafted optical lenses and bespoke microscopes and who made an extraordinary series of novel microscopic findings, including on protists, bacteria, spermatozoa and rotifers (Miall 1912;Dobell 1932). Although readily overlooked due to their size, species of Levenhookia can be impressive en masse, often growing in localised colonies of hundreds or thousands of plants. They are found in a wide variety of habitats, especially in south-western Australia where all but two of the species occur.
Levenhookia is the second largest genus in Stylidiaceae, a family dominated by the triggerplants (Stylidium Sw. ex Willd.), a diverse genus (> 300 spp.) renowned for its protandrous flowers with a touch-sensitive floral column that rapidly places pollen on, or retrieves pollen from, visiting insects (Erickson 1958;Findlay and Findlay 1975;Armbruster et al. 1994). Both genera have zygomorphic flowers with five corolla lobes, one of which (the labellum) is usually highly modified and variously ornate. In Stylidium, the labellum is typically reflexed and reduced in size to accommodate the column movement. In contrast, the labellum in Levenhookia is uniquely hooded (Fig. 2), enclosing the distal end of the column where the reproductive organs are located, and touch-sensitive (Brown 1810;Sargent 1918;Erickson 1958), springing backwards or opening when stimulated to expose the column (which can exhibit limited movement as a result). Unlike Stylidium, in which the column resets and retriggers after a short period of time, the movement of the labellum in Levenhookia and concomitant release of the column occurs just once.
Research by Brown (1810), Bentham (1837Bentham ( , 1868, Sonder (1845) and Mueller (1855Mueller ( , 1862Mueller ( , 1867 cumulatively led to the discovery of seven species of Levenhookia, three of which were originally named in the novel genus Coleostylis Sond. (Sonder 1845;Mueller 1855), but later transferred to Levenhookia (Mueller 1858(Mueller , 1864. Although a further four species have since been described Willis 1956, 1965;Carlquist 1969;Lowrie and Conran 2011), the genus lacks a modern taxonomic account, the most recent being that of Mildbraed (1908). That said, knowledge of the genus was greatly advanced by Erickson (1958) who observed a range of species in the wild and, like Leeuwenhoek, had a keen eye for detail.
Underpinning the present taxonomic study are 1740 collections of Levenhookia housed at various Australian herbaria, ca. 75% of which have been collected since the publication of Erickson's (1958) popular account. Sorting and verifying this material has been an arduous task given the size of the plants and the limited number of individuals associated with some collections; however, it has led to a much improved understanding of the distribution and conservation status of the included taxa. Herbarium-based studies also precipitated the discovery of a new species (L. aestiva Wege sp. nov.) endemic to the far south-west of Australia, material of which had previously been included under a broad concept of L. preissii Sond. (Sonder 1845;Mildbraed 1908;Erickson 1958;Wheeler 1987Wheeler , 2002Lowrie and Conran 2011). Levenhookia preissii is now considered to have a more restricted distribution on the heavily cleared landscape of Western Australia's Swan Coastal Plain bioregion and has recently been conservation-listed (Western Australian Herbarium 1998-). In contrast, the geographic distributions of L. pulcherrima Carlquist and L. murfetii Lowrie & Conran have been expanded through verification of herbarium records, the latter by more than 600 km (although the former remains poorly known).
Examination of historical collections has also proven invaluable, notably in the case of L. dubia Sond., a species widespread across southern Australia, but listed as extinct in Tasmania (with some uncertainty as to whether it ever occurred there: see Gray 2011). Specimens from Flinders Island and Pontville that were collected in the mid-to late 1800s, have been located at the National Herbarium of Victoria and not only confirm that it was indeed present in Tasmania, but can be used to provide information for future survey effort. Consideration of historical type material has also revealed several typification issues that are resolved herein to deliver a robust taxonomic framework.

Methods
This study is primarily based on the examination of herbarium material and associated spirit and photographic collections at the Western Australian Herbarium (PERTH), South Australian Herbarium (AD), Australian National Herbarium (CANB), Northern Territory Herbarium (DNA) and National Herbarium of Victoria (MEL). Specimens at the National Herbarium of New South Wales (NSW) were unavailable for study during this project. Distribution statements and maps are based on taxonomically validated specimen data, though collections of L. dubia from New South Wales that are housed at NSW have been included (these are likely to be correctly identified since this is the only species of Levenhookia recorded in this State). Type specimens at a range of additional institutions were also examined during research visitations, via specimen loans or through digital portals (indicated by image!): acronyms follow Thiers (2019). Geographic regions follow the Interim Biogeographic Regionalisation for Australia (Department of the Environment 2013).
Vegetative characters were mostly coded from pressed specimens, whereas floral characters were largely scored from wet collections, but supplemented with information gleaned from pressed material, field observations (mostly in south-western Australia) and photographic records. The exception is L. preissii, which has been described solely from pressed material and associated images, with flowers reconstituted from 2-lobed. Ovary inferior, with many ovules on a free-central placenta. Nectary sometimes present on top of the ovary. Capsules dehiscent. Seeds small, brown, rugulose, sometimes papillate.
Number of species, distribution and ecology. A genus of 12 species from a variety of habitats in southern temperate Australia, extending into the arid zone in Western Australia and the Northern Territory (Fig. 1A). The only representative of the genus in Tasmania is currently listed as extinct in that State (refer to the additional information provided under L. dubia). Some species are disturbance opportunists that are more readily found the year following a fire.
Floral morphology and pollination. The hooded labellum is responsive to touch, usually springing backwards through rapid recurvature of its claw, releasing the column ( Fig. 2A, D, F, H, I) before gradually repositioning itself at or above the level of the corolla lobes (Fig. 2B,E); it does not enclose the column or respond to  stimuli again. Levenhookia dubia is an exception since its sessile labellum opens to release the column, but does not otherwise move (Fig. 2J,K). As first noted by Erickson (1958), the exact point of stimulus varies amongst species: probing the apex of the hood or apical appendage will trigger the release of the column in L. dubia, L. leptantha, L. murfetii, L. octomaculata, L. pusilla and L. stipitata, whereas the labellum in L. aestiva and L. pauciflora is more reliably stimulated by touching the basal appendages. Erickson (1958) observed the sensitive point to be in the throat of the flower in L. preissii, something which I intermittently observed in L. aestiva. Sometimes the labellum cannot be manually triggered and it has been hypothesised that flowers await a certain stage of maturity before becoming responsive (Sargent 1918;Erickson 1958). In the absence of an external stimulus, growth of the upper-most stigmatic lobe, or apparently of the column itself, can sometimes trigger labellum movement (Erickson 1958).
The action of the labellum usually results in a degree of column movement (Fig. 2D,F,H,K), although movement is slight or lacking in both L. murfetii (Fig. 2I) and L. pusilla. These small-flowered species appear to be autogamous: the anthers dehisce within the labellum and the stigmatic lobes develop concurrently, becoming covered in pollen (Sargent 1918;pers. obsv.). In L. leptantha, L. aestiva and L. dubia, the column moves from the anterior to the posterior side of the flower, coming to rest against the column sheath at the base of the corolla lobes (Fig. 2D, F, K, respectively) before gradually shifting to an erect or slightly forward-arched position that maximises display of the stigmatic lobes (Fig. 2B,E). In L. aestiva, the column is long, free from the corolla tube and held under tension in untriggered flowers, moving rapidly when released from the labellum and coming to an abrupt stop when it hits the sheath. This catapult-like mechanism results in pollen being sprayed outwards from the anthers (and presumably onto a pollinator). In this species, the stigmatic lobes mature once pollen has been shed, thereby promoting outcrossing or geitonogamous self-pollination. The stigmatic lobes in L. pauciflora, L. preissii and L. pulcherrima similarly appear to mature once pollen has been shed.
In L. leptantha, the column is adnate to the anterior side of the corolla tube, with only the short (0.7-1.1 mm long), distal portion free to move. Despite this, a catapultlike action is still achieved. The distal portion, which is slightly forward-arched and therefore held under a degree of tension by the labellum, moves rapidly to the opposite (posterior) side of the flower when the labellum is triggered, with its forward momentum apparently halted by its attachment to the anterior side of the corolla tube (the posterior rim of the column sheath may also act as a stopper). Like L. aestiva, pollen is sprayed outwards from the anthers, but may also spill onto the lower stigmatic lobe which, in contrast to L. aestiva, develops before the upper one and usually while the column is still enclosed by the labellum. The lower stigmatic lobe, which is strongly upturned, can often be seen protruding from the labellum and this may enable it to receive pollen from a visiting insect. The upper stigmatic lobe matures once the column has been exposed from the labellum and is prominently displayed to promote outcrossing. Staggered development of the stigmatic lobes is also evident in L. chippendalei, L. dubia, L. octomaculata and L. stipitata, of which L. dubia is akin to L. leptantha in having the column adnate to the corolla tube (a trait also shared with L. pauciflora, L. pulcherrima and possibly L. sonderi).
Levenhookia pauciflora has a distinct column morphology that generates a unique movement. In addition to adhering to the corolla tube, the column is attached to the anterior side of the column sheath, which further restricts its movement upon release from the labellum. Its distal end (Fig. 2H) is sharply angled towards the labellum and has a dilated tip subtended by a weak hinge. The hinge provides the tip with a degree of flexibility that may enable direct placement of pollen on an insect. Erickson (1958) noted that this species produced "a veritable shower" of pollen when triggered; however, I observed its column to move comparatively slowly into a nearly upright position without generating an obvious spray of pollen, although some pollen was transferred to the prominent tuft of hairs at the apex of the labellum, potentially functioning as a form of secondary pollen presentation. Erickson (1958) suggested that the release of the column from the labellum in Levenhookia results in geitonogamous self-pollination via the catapulting of pollen between flowers on the same plant. This is at odds with my own observations, which indicate that the flowers are usually too widely spaced and pollen is not flung far enough for this to occur. Furthermore, in some species (L. dubia, L. pauciflora, L. octomaculata and L. stipitata), I observed little to no pollen spray; however, further observations are warranted, particularly given the suggestion that the column is held under increasing tension as the flower matures (Erickson 1958: 206). This suggests that variation is to be expected when studying flowers within a population or even on the same plant.
The interaction between the labellum and the column, which is difficult to investigate in the field given the size of the plants and the rapidity of the movements, remains incompletely studied. Observations are lacking for many species and pollination records are largely wanting. Erickson (1958: 203) noted woolly bee-flies actively probing flowers of L. leptantha, noting that pollen grains were "sprayed about the head and under the body". I have only made two incidental observations: a small native bee on L. pulcherrima (at J.A. Wege 1937), moving rapidly between flowers while foraging for pollen and a large wasp repeatedly visiting L. octomaculata (at J.A. Wege 2074), although it was unclear whether it was transferring pollen between flowers.
Other notes. Erickson (1958: 200) notes that Levenhookia flowers close at night by folding the four main corolla lobes together. I have observed this phenomenon in L. aestiva, L. dubia, L. leptantha and L. octomaculata; however, this trait is not universally exhibited, with the small flowers of L. murfetii and L. pusilla remaining open. Mildbraed (1908) recognised three sections based on labellum and column sheath morphology (at which time only six species were recognised). A revised infrageneric classification will be considered once a robust molecular phylogenetic framework is available, although this is unlikely to be warranted given the size of the genus.

A key to the species of Levenhookia
Note that column length can be estimated on pressed material by measuring from the tip of an exposed column to the base of the calyx lobes. Description. Annual herb 1-10 cm high. Glandular hairs ca. 0.1-0.2 mm long. Stem dark red, simple or branched to varying degrees with porrect lateral branches, mostly glabrous, a few glandular hairs sometimes present distally on the lateral branches. Leaves cauline, scattered, green adaxially, dark red or purplish red abaxially; lamina oblanceolate to narrowly oblanceolate, reniform, ovate or elliptic, 1.5-15 mm long including the petiole, 1-6.5 mm wide, obtuse or subacute, glabrous or scarcely papillate. Flowers in corymbs, usually crowded amongst the bracts, 1-500 + per plant; bracts narrowly oblanceolate to oblanceolate or linear, 1.8-9 mm long, usually glabrous, sometimes scarcely papillate on the margins, the upper-most bracts sometimes with a few glandular hairs abaxially towards the base; pedicels 0.3-2.5 mm long, sparsely glandular-hairy. Hypanthium globose, ellipsoid or ovoid, 0.7-1 mm long, 0.6-0.9 mm wide, with glandular hairs throughout and eglandular hairs 0.2-0.6 mm long distally. Calyx lobes subequal (with the anterior pair scarcely longer than the rest), 1-1.7 mm long, acute or subacute, glabrous or sparsely glandular-hairy towards the base, sometimes scarcely papillate apically. Corolla pink with a white base or occasionally all white, glabrous; lobes evenly arranged or sometimes ± paired vertically, distally recurved, obovate, ± equal in size or with the anterior pair scarcely longer than the posterior ones, 0.9-1.5 mm long, 0.6-0.9 mm wide, rounded or scarcely apiculate; tube white, 0.3-0.6 mm long, shorter than the calyx lobes. Labellum dorsal or sometimes ventral (rarely lateral), 0.7-0.8 mm long including a 0.1-0.2 mm long claw; hood dark red-pink or red-purple, usually sparsely glandular-hairy abaxially, minutely papillate adaxially along the margins; appendage at the cleft apex red-pink, ca. 0.1-0.2 mm long, papillate; basal appendages white, linear-subulate, ca. 0.3 mm long. Column sheath creamy white, glabrous, irregularly lobed, to 0.3 mm high, pendulous appendages absent. Column white, often tipped red-pink, free, 1-1.5 mm long, distally broadened and angled toward labellum, glabrous; stigmatic lobes to 0.4 mm long, developing while the column is hooded, erect to incurved. Capsule ovoid, 1.3-3 mm long excluding calyx lobes. Seeds 0.4-0.7 mm long, 0.3-0.4 mm wide.
Diagnostic features. Levenhookia pusilla has a dark red and glabrous primary stem axis, glabrous or scarcely papillate leaves and outermost bracts that are usually green adaxially and dark red or purplish red abaxially, and tiny flowers with a pink and white (occasionally all white) corolla with lobes 1-1.5 mm × < 1 mm.
Phenology. Flowering from mid-September to early December; fruiting from October to early January.
Distribution. Levenhookia pusilla has a disjunct distribution in southern Australia (Fig. 3A). In south-western Australia, it is common in the Jarrah Forest, Warren and Swan Coastal Plain bioregions and scattered across the southern Avon Wheatbelt, Mallee and Esperance bioregions, with one outlying record from the Geraldton Sandplains. In south-eastern Australia, it is restricted to the Flinders Lofty Block, Eyre York Block, Murray Darling Depression, Naracoote Coastal Plain and Kanmantoo bioregions in south-eastern South Australia, extending into Victoria at Little Desert National Park near the South Australian border.
Habitat. This species grows in sand or loamy sand on ridges, hill-slopes, plains or dune swales, often with lateritic gravel or in association with granite outcropping; it is more rarely recorded growing in clay or clay loam in depressions or seasonally-wet flats. Associated vegetation is varied and includes tall Eucalyptus woodland or forest, low open woodland with Eucalyptus, Allocasuarina or Melaleuca, shrubland or scrub with Banksia, Melaleuca or emergent mallees, and low heath. It commonly co-occurs with L. stipitata in Western Australia and is often abundant on firebreaks and along track edges.
Conservation status. Levenhookia pusilla is widespread and locally abundant across most of its range (IUCN (2012): Least Concern), but it is listed as Vulnerable in Victoria (Department of Environment and Primary Industries, Victoria 2014), where it is restricted to Little Desert National Park.
Etymology. From the Latin pusillus (very small); an aptly named plant given its tiny flowers and diminutive habit. Vernacular name. Midget Stylewort (Erickson 1958). Notes. Levenhookia pusilla is morphologically allied to L. murfetii (refer to the comparative notes under that species) and the two species are known to grow near one another in Western Australia's Avon Wheatbelt. It often has a dorsally positioned labellum, a feature shared with L. murfetii and achieved through rotation of the pedicel; however, a ventral or lateral labellum has also been observed in instances where the crowded flowers and bracts prevent rotation or full rotation of the pedicels.
A specimen of L. pusilla from the Geraldton Sandplains bioregion near Warradarge (M. Hislop 1492, PERTH) is a northern outlier: further collections and observations from this region would be of interest, particularly given the widespread occurrence of L. murfetii in this area.
Diagnostic features. Levenhookia murfetii has a stem that is glabrous basally and glandular-hairy distally, bracts with glandular hairs restricted to the undersurface, and a pink or white corolla with small lobes (1-2 mm long) bearing a small red-pink marking towards the base.
Phenology. Flowering from late August to early October; fruits have been collected in October.
Distribution. Levenhookia murfetii is endemic to south-western Australia (Fig. 3C) where it occurs in the Geraldton Sandplains, Avon Wheatbelt and Mallee bioregions, from Eurardy Station to east of Grass Patch.
Habitat. This species usually grows in sand or sandy loam (rarely in clay loam), often with lateritic gravel (rarely with decomposed granite). It is commonly recorded in low heath, mallee shrubland, tall Allocasuarina or Melaleuca shrubland, and Eucalyptus wandoo woodland. It is often abundant on firebreaks or near the base of open shrubs.
Conservation status. This widespread species is locally abundant at a range of sites (IUCN 2012: Least Concern).
Etymology. Honours Denzel E. Murfet, who is affiliated with the State Herbarium of South Australia and has made more than 650 Stylidiaceae collections from across Australia (AVH 2019). Vernacular name. Kwongan Stylewort. Notes. Lowrie and Conran (2011) described L. murfetii from a limited number of specimens collected from north and north-east of Perth. Examination of collections at PERTH indicate a much broader geographic range and reveal that some of the features they used to separate it from L. pusilla are not taxonomically informative, most notably whether the stem is simple or branched, labellum morphology and inflorescence structure. The simplest way to distinguish pressed material of these two species is by examining the distal portion of the stem and the abaxial surface of the outermost floral bracts, which are always glandular-hairy in L. murfetii and glabrous in L. pusilla. Levenhookia murfetii mostly flowers earlier in the season (from late August to early October cf. late September to early December) and its flowers tend to have more openly-spread corolla lobes (compare Fig. 3B, D) with discrete red-pink markings near the base (Fig. 2I) (markings absent in L. pusilla). While individual plants of L. murfetii often produce fewer flowers than in L. pusilla, flower number cannot be used to reliably separate these two species. They are largely geographically separated, although an apparent mixed collection from the Bolgart area (R. Erickson s.n., PERTH 02769182) suggests that they may occur in sympatry. They are known to grow in proximity to one another in the Tarin Rock and Toodyay areas and probably also near Warradarge (refer to the notes under L. pusilla).

Levenhookia sonderi
Diagnostic features. Levenhookia sonderi has a pale, sparsely glandular-hairy stem, leaves with an ovate or orbicular lamina, glandular and eglandular hairs on the hypanthium, unequal calyx lobes with obtuse to subacute apices, and a red-purple labellum (appearing very dark on pressed material) with white, linear-subulate basal appendages. Its seeds are the largest in the genus.
Phenology. Flowering September-December; fruiting October-December. Distribution. Levenhookia sonderi is endemic to South Australia and Victoria (Fig. 3E), where it is has been recorded from the Naracoote Coastal Plain, Southern Volcanic Plain, Victorian Midlands and South Eastern Highlands bioregions, extending from Reedy Creek (South Australia) in the west to the Dandenong Ranges (Victoria) in the east.
Habitat. This species grows in damp sandy loam or clayey sand on hill-slopes or more commonly in lowland areas, including near the margins of swamps. Populations of this species are isolated and appear highly localised, with the reproductive capacity of some individuals from locations in South Australia and Victoria impacted by a species of smut (see notes below).
Etymology. Honours German apothecary and botanist Otto Wilhelm Sonder (1812-1881), who described a suite of new taxa as part of his account of Stylidiaceae in Lehmann's Plantae Preissianae (Sonder 1845).
Vernacular name. Slender Stylewort (Erickson 1958). Typification. MEL 1617988, which is annotated by Mueller and was viewed by Bentham (1868) for Flora Australiensis, comprises a mounted individual and an envelope housing five separate packets that represent more than one gathering. The mounted individual and the numerous additional plants in the large, cream, rectangular packet annotated "Levenhookia Sonderi, Mueller's" have been selected as an appropriate lectotype. This material is comparable to that of K 000060054, MEL 1617989 and MEL 2256398-they are at the same flowering stage and bear white mycelia, presumably from being poorly dried following their collection-and showcases the distinctive, dark labellum, which Mueller notes on the label ("labellum atropurpureum!"). Material at TCD is also interpreted as being part of this gathering.
The remaining material on MEL 1617988 is not treated herein as type material. There is a blue, rectangular packet annotated "Coleostylis sonderi Portland" that contains a single flowering plant, which Mueller may have separated from MEL 2256407 to send to Bentham. There is a smaller blue packet annotated "Leeuwenhoekia sonderi" that contains flower fragments, but it is unclear to which gathering they belong. Finally, there are two packets containing seeds and withered corolla fragments that must be from a separate collection to that of the type gathering, which is not in fruit. It is unknown whether these seeds are from the type population or from a different locality or, indeed, two separate localities. It is of note that there are no fruiting specimens at MEL that predate the publication of this species and Mueller did not describe seed in the protologue. Seed is also inexplicably present in the packet attached to Portland's flowering collection (MEL 2256407).
Notes. Levenhookia sonderi is most likely to be confused with L. dubia, a species with which it can co-occur (there have been mixed collections made of the two (e.g. D.J. Van Bockel 195A and 195B, MEL;H.B. Williamson s.n., MEL 2256403). Their superficial similarity led Mildbraed (1908) to treat L. sonderi as a variety of L. dubia, but it was reinstated as a distinct species by Erickson (1958) on account of its dark red-purple labellum hood (cf. cream to yellow or pale pinkish red), green stems (cf. reddish) and shorter corolla tube (0.9-1.3 mm long and shorter than the longest calyx lobes cf. 1.5-3 mm long and ± equal to or longer than the calyx lobes). While stem colour cannot be used to reliably separate the two species, labellum colour and corolla tube length are informative and can be observed on pressed material. Levenhookia sonderi can be further separated from L. dubia by its unequal and obtuse or subacute calyx lobes (cf. equal and acute), hypanthium indumentum of both glandular and eglandular hairs (cf. glandular-hairy), linear-subulate basal appendanges on the labellum (cf. appendages lacking or rudimentary and rounded) and larger seed (0.6-1 mm long cf. 0.25-0.4 mm). It also tends to have more rounded leaf apices than L. dubia.
The column of L. sonderi appears to be adnate to the corolla tube like that of L. dubia, although this requires verification given the limited spirit material available for study. In one dissected flower, both stigmatic lobes were developed under the labellum hood with copious pollen observed. Like L. pusilla and L. murfetii, this suggests autogamy; L. sonderi is certainly akin to these two species, with all three sharing an indumentum of both eglandular and glandular hairs on the hypanthium. Some individuals on the following collections of L. sonderi from South Australia and Victoria are infected by a smut that proliferates in the ovary, preventing the production of flowers and seed:  Description. Annual herb 1.2-9 cm high. Glandular hairs 0.1-0.5 mm long. Stem dark red or pale reddish to greenish brown, simple or with porrect lateral branches, glandular-hairy. Leaves cauline, scattered, green or reddish; lamina ovate, oblanceolate, lanceolate or elliptic, sometimes narrowly so, 1-10 mm long including the petiole, 0.5-3 mm wide, subacute to acute, glandular-hairy abaxially and on the margins, sometimes also adaxially near the base. Flowers in short racemes or corymbs, 1-40(-ca. 70) per plant; bracts oblanceolate, lanceolate or elliptic (sometimes narrowly so), 1.2-9 mm long, glandular-hairy like the leaves; pedicels 0.5-5(-10) mm long, glandularhairy. Hypanthium depressed globose to globose, ellipsoid or obovoid, 0.7-2.2 mm long, 0.7-1.8 mm wide, glandular-hairy. Calyx lobes ± equal, 0.7-2.2 mm long, acute, glandular-hairy. Corolla white or more rarely pale pink, with a yellow throat, rarely with faint red-pink markings at the base the lobes; lobes ± equal and evenly arranged or with the anterior (lower) lobes scarcely longer and broader than the posterior pair, spreading to scarcely recurved, obovate or elliptic, 1.2-3 mm long, 0.8-2 mm wide, retuse or rounded, glabrous or with a few glandular hairs abaxially towards base; tube 1-3 mm long, ± equal to or up to 1.2 mm longer than the calyx lobes, white, sparsely glandular-hairy distally. Labellum ventral, 0.6-1 mm long, ± sessile; hood yellow to whitish, sometimes with pinkish red markings, sparsely glandular-hairy abaxially, without an appendage at the cleft apex; basal appendages absent or rudimentary and obtuse. Column sheath yellowish, glabrous, reduced to a scarcely lobed rim to ca. 0.2 mm high on the anterior side, connate with the posterior corolla lobes forming a smooth, thickened pad, pendulous appendages absent. Column creamy yellow, adnate to the anterior side of the corolla tube, 1.3-2.5 mm long with the top 0.5-0.8 mm free and gently forward-arched when enclosed by the labellum, glabrous; stigmatic lobes to ca. 0.3 mm long, the lower-most sharply upturned and developing while the column is hooded, the upper lobe incurved and developing later. Capsule globose, ovoid or obovoid, 1.2-2.2 mm long excluding calyx lobes. Seeds 0.25-0.4 mm long, 0.2-0.3 mm wide.

Levenhookia dubia
Diagnostic features. Levenhookia dubia has a glandular-hairy stem, acute calyx lobes, a corolla tube roughly equal to or a little longer than the calyx lobes, and a ±sessile labellum that lacks an apical appendage.
Phenology. Flowering from August to November, with fruits recorded from mid-September to November.
Distribution. Levenhookia dubia is widespread across southern mainland Australia, with records spanning near coastal areas to the semi-arid interior (Fig. 4A). There are several historical collections from mainland Tasmania and Flinders Island from the 1800s (see additional information under 'Conservation status').
Habitat. Levenhookia dubia grows in sand, sandy loam or clay loam, often in depressions or shallow drainage areas, near creek-lines or in damp soils associated Conservation status. This widespread species is not currently considered to be at risk (IUCN 2012: Least Concern); however, it is currently listed as extinct in Tasmania under the Tasmanian Threatened Species Protection Act 1995 (Tasmanian Government 2019). Although historically recorded from Brighton, Flinders Island and Mount Field (Spicer 1878;Rodway 1903), the sole collection from this State at the Tasmanian Herbarium is one by William Archer that lacks locality information; accordingly, the veracity of these early works has been questioned (e.g. Gray 2011). I have recently viewed material collected in Tasmania at the National Herbarium of Victoria, specifically, collections by William Spicer (from Pontville near Brighton: MEL 2257574, 2257575 and 2257577) and Joseph Milligan (from the Strzelecki Peaks on Flinders Island: MEL 2257576) that support a distribution that includes Tasmania and provide information for future survey efforts. Appropriately timed searches in the Strzelecki National Park that focus on herb fields, moss beds or open runoff areas associated with granite outcropping, may lead to its rediscovery. In the absence of a corresponding voucher, the Mount Field locality of Rodway (1903) cannot be confirmed and is interpreted as a likely error.
Etymology. From the Latin dubius (doubtful), alluding to Sonder's (1845) uncertainty with regards to its generic classification. Vernacular name. Hairy Stylewort (Erickson 1958). Typification. Sonder examined and annotated specimens of L. dubia in his personal herbarium (now at MEL), as well as material at BM and LD, all of which conform to the protologue. The designated lectotype (MEL 2257601) is the best quality material.
Notes. In south-eastern Australia, L. dubia may be confused with L. sonderi (refer to the comparative notes under that species).

Levenhookia leptantha
Diagnostic features. Levenhookia leptantha has succulent floral bracts, a long (3-9 mm) corolla tube and comparatively short (0.8-2 mm long) calyx lobes, and minute glandular hairs at the tip of the column. Its corolla lobes are usually bright pink with a yellow base and the labellum has a morphologically distinct apical appendage that can be discerned on pressed material.

Phenology.
Flowering from late August to October. Distribution. Levenhookia leptantha is widespread in south-western Australia (Fig. 4C), although largely absent from the high rainfall zone, with most records occurring in the Geraldton Sandplains, Yalgoo, Avon Wheatbelt and Coolgardie bioregions. There are scattered occurrences in the Murchison and Mallee bioregions and an isolated record from the Swan Coastal Plain near Muchea.
Habitat. Levenhookia leptantha grows in sand, sandy loam, sand over clay or clay loam on plains and gentle hill-slopes, often in association with granite outcropping, salt lakes, creek-lines or seasonally wet claypans. Associated vegetation is varied and includes open Eucalyptus woodland, mallee shrubland, tall shrubland or scrub with Acacia, Allocasuarina, Melaleuca or Eremophila, and halophytic dwarf shrubland. It is often found in more open areas of habitat growing with other ephemeral herbs.
Conservation status. This widespread species is not currently considered to be at risk (IUCN 2012: Least Concern).
Etymology. From the Greek lepto-(slender-) and anthos (flower): the flowers can appear narrow in pressed material due to their long and slender corolla tube. Vernacular name. Trumpet Stylewort (Erickson 1958). Typification. Bentham examined several gatherings when describing L. leptantha, including "a few specimens mixed in Preiss's n. 2249" (a syntype of L. preissii). MEL 2295747 bears his corresponding annotation "These specimens seem rather to belong to L. leptantha, the lower ones to L. preissii"; however, I am at a loss to explain Bentham's interpretation of this material. All individuals on this sheet appear referable to L. aestiva (refer to the typification section under L. preissii). A lectotype must therefore be selected from amongst the remaining material to fix the application of the name L. leptantha. MEL 2257568 has been selected since it is the best quality material with specific locality information that was viewed by Bentham. It bears a Botanical Museum of Melbourne label with the locality "Murchison River" as given by Mueller, an Oldfield label with the annotation "337. Fl. Pink. Moist places. Thicket south of Collallia" [Colalya Creek, which drains into the Murchison River east of Meekatharra] and a slip with "Gerald river Murchison" in Bentham's hand. Bentham also retained a subset of this material at K.  UC n.v., US n.v.).
Description. Annual herb 3-16 cm high. Glandular hairs 0.15-4 mm long. Stem dark red, often paler distally, simple or with porrect or ascending lateral branches, glandular-hairy. Leaves cauline, scattered, green adaxially, green or reddish abaxially; lamina oblanceolate to narrowly oblanceolate, lanceolate, ovate or elliptic, 4-22 mm long including the petiole, 1-5 mm wide, obtuse to subacute, sparsely glandular-hairy near the base on the margins and abaxial surface. Flowers in umbels, corymbs or a more elongated raceme, (1)3-ca. 100 per plant; bracts narrowly oblanceolate to almost linear, 4-20 mm long, glandular-hairy like the leaves; pedicels 0.5-4 mm long, glandular-hairy. Hypanthium depressed globose to globose or ellipsoid, 0.8-1.5 mm long, 0.7-1.3 mm wide, glandular-hairy. Calyx lobes subequal (with the anterior-most a little longer than the rest), 1.8-3.5 mm long, acute, sparsely to moderately glandular-hairy. Corolla bright to pale pink with a white throat (more rarely all white) and prominent dark pink markings on the posterior (upper) lobes; lobes paired vertically, spreading to scarcely recurved, obovate, incised or emarginate, usually with a few glandular hairs abaxially towards the base; anterior (lower) lobes slightly inwardly curved, a little longer and broader than the posterior (upper) lobes, 3.2-5 mm long, 2.5-3.6 mm wide; posterior lobes 3-4.5 mm long, 2.2-3.5 mm wide; tube 4.8-8 mm long, 2.5-5 mm longer than the calyx lobes, creamy white with pink-red longitudinal streaks, sparsely glandular-hairy distally. Labellum ventral, 1.3-2 mm long including a claw 0.2-0.4 mm long; hood purplish-red hood (drying dark red-maroon) with pinkish markings near the cleft, sparsely glandular-hairy abaxially, papillate adaxially along the margins of the cleft, cleft apex with a tuft of yellowish or whitish hairs; basal appendages creamy white, linear-subulate, 0.5-0.6 mm long. Column sheath creamy white, glabrous, with a narrowly triangular, obtuse, posterior lobe to 1 mm high and rounded anterior and lateral lobes 0.5-0.8 mm high, pendulous appendages absent. Column creamy-white, adnate to the anterior side of the corolla tube, 6.5-9 mm long with the top 1.5-2 mm free and angled toward the labellum, faintly constricted below the anthers, glabrous; stigmatic lobes to 1.2 mm long, apparently developing once the column has been exposed, the lowermost arching downwards, the uppermost straight to incurved. Capsule ovoid or globose, 2.5-4 mm long excluding calyx lobes. Seeds ca. 0.5 mm long, 0.3 mm wide.
Diagnostic features. Levenhookia pulcherrima has an exserted corolla tube that is 4.8-8 mm long, incised or emarginate corolla lobes with dark pink marking near the base of the upper pair, and a shortly-stalked labellum with linear-subulate basal appendages and a small tuft of hairs at the tip.
Phenology. Flowering from September to November; fruiting recorded from late October and November (and presumably extending into December).
Distribution. Levenhookia pulcherrima is endemic to south-western Australia (Fig. 4E), where a small number of populations have been recorded from the central Avon Wheatbelt between Northam, Kellerberrin and Pingelly, and the Esperance Plains, Mallee and Coolgardie bioregions, from near Ravensthorpe to east of Forrestania.
Habitat. This species grows in sand or loamy sand on floodplains, outwash hillslopes or adjacent to granite outcropping. Associated vegetation includes Acacia acuminata woodland, Allocasuarina shrubland or scrub, mallee woodland or heath, or low open heath.
Conservation status. This species is listed as Priority Three under Conservation Codes for Western Australian Flora (Western Australian Herbarium 1998-) (equivalent to IUCN (2012): Data Deficient). It remains poorly-known despite the discovery of seven new populations through assessment of herbarium collections and recent field surveys. Obtaining population data for this species is difficult since it is most abundant following fire (e.g. J. A. Cochrane 6906 & B. Davis,PERTH;D.J. Edinger 935,PERTH;G.J. Keighery 466,PERTH). A new population was surprisingly discovered in 2014 in a botanically well-surveyed nature reserve in the Avon Wheatbelt (J. Borger & N. Moore MC 9-1, PERTH) growing in unburnt habitat adjacent to experimental patch burns, suggesting that the smoke from these fires may have triggered germination. It is not known how long the soil seed bank remains viable and, as such, inappropriate fire regimes may represent a threat to this species.
Etymology. From the Latin pulcherrimus (prettiest). Vernacular name. Beautiful Stylewort. Notes. Several collections of L. pulcherrima were previously misidentified as L. leptantha, a species with a similarly long corolla tube. Pressed material of L. pulcherrima can be separated from L. leptantha by its mostly longer calyx lobes (1.8-3.5 mm cf. 0.8-2 mm) and morphologically distinct labellum, which has linear-subulate basal appendages and an apical tuft of hairs (cf. with rounded basal appendages and a small, glabrous apical appendage). Levenhookia pulcherrima lacks the succulent leaves and bracts that characterise L. leptantha and the posterior side of its column sheath has a prominent triangular lobe (cf. sheath connate with the posterior corolla lobes to form a smooth, yellow pad).
Diagnostic features. Levenhookia pauciflora has a stem with both glandular hairs and minute papillae, creamy white corolla lobes with a fine red midvein on the undersurface, upper corolla lobes with pointed tips, and a brush-tipped appendage at the apex of the labellum cleft. Its column and column sheath morphology are diagnostic but less readily viewed on pressed material.
Phenology. Mostly flowering from September to early November (rarely in January as per type gathering); fruits have only been collected in October.
Distribution. Levenhookia pauciflora is widespread in south-western Australia (Fig. 5A), extending from Badgingarra and Watheroo National Parks in the Geraldton Sandplains bioregion, south to Scott River National Park in the Warren bioregion, and east to Cape Arid National Park in the Esperance bioregion, with numerous records from the central Avon Wheatbelt and Mallee bioregions.
Habitat. Levenhookia pauciflora is found on plains or hill-slopes in sand or clayey sand, sometimes with surface gravel or in association with granite outcropping. Associated vegetation is varied and includes heath, mallee shrubland, open Eucalyptus or Corymbia woodland, and scrub with emergent Nuytsia or Banksia.
Conservation status. This is a widespread species that is not currently considered to be at risk (IUCN 2012: Least Concern).
Etymology. From the Latin paucus (few) and -florus (-flowered). Vernacular name. Deceptive Stylewort (Erickson 1958). The corolla lobes of this species are reminiscent of some triggerplants including Stylidium petiolare Sond., with which it can co-occur. Typification. I annotated W 0047174 as a syntype during a visit to the Naturhistorisches Museum Wien in 2003 but have since failed to find any other duplicates of Hügel's gathering. This sheet, which has been annotated by Bentham, is therefore regarded here as the holotype.
Diagnostic features. Levenhookia preissii has a long (2-4.5 mm) corolla tube that is exerted beyond the calyx lobes, pink corolla lobes with speckled markings, a long labellum (ca. 3-4.2 mm) with rounded basal appendages and a prominent (0.7-1.5 mm long) apical appendage, and a 4.5-7.2 mm long column subtended by a lopsided column sheath. Its racemes are usually quite elongated (especially in floriferous individuals).
Phenology. Flowering from late October to January; fruiting in December and January.
Distribution. Levenhookia preissii is endemic to south-western Australia (Fig. 5C), where it is restricted to the Swan Coastal Plain bioregion. It is currently known from north-west of Cataby and the Perth metropolitan area, although historical records indicate a distribution that extends south to the Pinjarra area.
Conservation status. Levenhookia preissii was recently listed as Priority One under Conservation Codes for Western Australian Flora (Western Australian Herbarium 1998-;equivalent to IUCN (2012): Data Deficient). It is currently known from two bushland fragments in Perth and from an area north-west of Cataby that is subject to mining. Few plants have been noted with the exception of B.J. Keighery 2546, which was collected the year following a summer fire. The optimal time for survey and conservation assessment is during peak flowering (between mid-November and mid-December), following a summer or autumn fire.
Etymology. Honours Johann August Ludwig Preiss (1811-1883), who collected extensively in south-western Australia between 4 December 1838 and 8 January 1842 (George 2009). These collections formed the basis for Lehmann's Plantae Preissianae, a landmark work on Western Australian botany in which a suite of Stylidiaceae taxa were described (Sonder 1845).
Vernacular name. Preiss's Stylewort (Erickson 1958). Typification. Sonder based his description of Coleostylis preissii on three separate gatherings of which Preiss 2250 (from the Perth suburb of Guildford) and Drummond 515 ('Swan River') are comparable; however, Preiss 2249 (from the more southerly 'Sussex District', i.e. between Capel and Toby's Inlet: see Marchant 1990) represents a distinct species. Lectotypification is necessary to fix the application of the name L. preissii.
Sonder viewed material of both Preiss gatherings at LD and in his personal herbarium, which is now at MEL. The LD material is fragmentary, comprising one or two inflorescence portions. The Preiss material at MEL is more complete but difficult to interpret-there are few readily visible flowers, labelling is ambiguous and one of the sheets (MEL 2295750) contains material from both gatherings. This sheet includes four individuals, several floral dissections and Sonder's sketches and notes (which indicate that he observed differences in labellum size and appendage morphology between the two gatherings). The uppermost individual belongs to Preiss 2250, while the remaining three individuals appear to match Preiss 2249. I have not been able to confidently assign all fragments contained in the attached packet, but I have separated several that seem to be referable to Preiss 2250, including dissected flowers. I have been unable to find a dissection for Preiss 2249 despite Sonder's floral sketches.
Given the difficulties associated with interpreting the Preiss material at MEL, the fragmentary nature of the duplicates at LD and, indeed, the generally poor quality of the material, I have made the pragmatic decision to lectotypify on the Drummond gathering despite its lack of precise locality. Based on our present day understanding of the species and Drummond's collecting trips (see George 2009), it is likely to have been collected from the Perth region. BM 000984007 is designated as the lectotype: it comprises four, mostly complete individuals with ample floral material, a small packet with some fragments and a pink annotation slip with the name 'Coleostylis racemiflora Sond.' in Sonder's hand (an earlier manuscript name that he also wrote on a subset of 9. Levenhookia aestiva Wege, sp. nov. urn:lsid:ipni.org:names:77209908-1 Figs 2B, 5F, 6. Diagnosis. Levenhookia aestiva can be identified by its long (5.5-8 mm) corolla tube, long (7.5-11 mm) column, entire column sheath with 3 pendulous appendages, and long labellum (4.5-6.5 mm) with a prominent apical appendage and oblong-subulate basal appendages. Description. Annual herb 4-15 cm high. Glandular hairs somewhat viscid, 0.2-0.6 mm long. Stem dark red or brownish red, simple or branched to varying degrees with porrect or ascending lateral branches, glandular-hairy. Leaves cauline, scattered, green or red, glandular-hairy on the margins and abaxially, with a few hairs adaxially (mostly towards the base); lamina narrowly oblanceolate to oblanceolate, elliptic or ovate, 3-25 mm long including the petiole, 1-5.5 mm wide, acute to subacute with a blunt tip. Flowers in racemes (inflorescence corymbose in few-flowered individuals), 1-ca. 300-flowered; bracts narrowly oblanceolate to oblanceolate, narrowly lanceolate or ± linear, 2-22 mm long, glandular-hairy like the leaves; pedicels 1-6 mm long, glandular-hairy. Hypanthium globose, obovoid or depressed-obovoid, 0.7-1 mm long, 0.8-1.5 mm wide, glandular-hairy. Calyx lobes subequal (with the anterior pair scarcely longer than the rest and rarely connate basally), 2.5-4.2 mm long, acute, glandularhairy. Corolla pink, often with a dark pink midvein and with white or pale pink margins near the base of the lobes; lobes evenly arranged tending vertically-paired, elliptic or obovate with a slender claw, usually slightly recurved, sparsely glandular-hairy abaxially towards the base and along the midvein; anterior (lower) lobes slightly narrower than the posterior pair, 4.5-6.5 mm long, 2.2-3.2 mm wide, bluntly pointed or rounded; posterior (upper) lobes 4.5-6 mm long, 2.8-3.5 mm wide, bluntly pointed; tube whitish with pink longitudinal stripes distally, 5.5-8 mm long, exserted 1.5-4.5 mm beyond the calyx, sparsely glandular-hairy distally. Labellum ventral, 4.5-6.5 mm long including a 1.5-2.5 mm long claw; hood pink with dark red-purple markings adaxially, minutely papillate, sometimes with a few glandular hairs abaxially; basal appendages creamy white, pale yellow near the base, oblong-subulate, 1-2.5 mm long, acute or obtuse, sometimes papillate; appendage at the cleft apex pink, elliptic to obovate, 1.5-2 mm long, 0.8-1.4 mm wide, usually with an irregularly incised apex (rarely obtuse), glabrous. Column sheath deep pink, glabrous, 0.5-1 mm high, with an entire, thickened rim bearing 3 pendulous appendages on the inside. Column white basally, pinkish distally, free, forward-arched when enclosed by the labellum, slender but slightly thickened distally, 7.5-11 mm long, glabrous; stigmatic lobes to 1.3 mm long, incurved, apparently maturing subsequent to pollen release. Capsule depressed obovoid, 1.5-3 mm long excluding calyx lobes. Seeds 0.4-0.5 mm long, 0.2-0.3 mm wide.
Phenology. Mostly flowering from mid-November to early February, with flowering extending into March and April in swampy habitats on the south coast; mostly fruiting from mid-December to February.
Distribution. Most records of L. aestiva are from the south-west corner of Western Australia (Fig. 5E) between Bunbury, Pemberton, Augusta and Yallingup in the Warren, Jarrah Forest and Swan Coastal Plain bioregions. There is an outlying, but morphologically comparable record near Denmark.
Habitat. Levenhookia aestiva grows in sandy soils near swamps and on low lying flats, or in sandy loam with lateritic gravel in more upland habitats. It is commonly recorded from post-fire habitats and disturbed roadsides or firebreaks. Associated vegetation includes open Eucalyptus marginata, Corymbia calophylla or C. haematoxylon woodland with Kingia australis and Xanthorrhoea preissii, and low Myrtaceous shrub- land. In lateritic habitats, it may grow in sympatry with Stylidium lateriticola Kenneally, a species with similarly bright pink, summer-blooming flowers.
Conservation status. Despite its reasonably narrow geographic range, L. aestiva is locally common at numerous sites within the conservation estate (especially following a disturbance) and is not currently considered to be at risk (IUCN (2012): Least Concern).
Etymology. From the Latin aestivus (of summer), in reference to its flowering time. Vernacular name. Summer Stylewort. Notes. Specimens of L. aestiva have previously been placed under a broadly defined L. preissii (Sonder 1845, Mildbraed 1908, Erickson 1958, Wheeler 2002, Lowrie and Conran 2011; however, there are several features that support its recognition as a distinct species. Corolla tube length (5.5-8 mm cf. 2-4.5 mm in L. preissii) and column length (7.5-11 mm cf. 4.5-7.2 mm in L. preissii) are taxonomically informative and readily observed on pressed material. Levenhookia aestiva also has a longer labellum (4.5-6.5 mm cf. 3-4 mm) with a larger apical appendage (1.5-2 mm × 0.8-1.4 mm cf. 0.7-1.5 × 0.4-0.6 mm) and longer basal appendages (1-2.5 mm cf. 0.4-0.7 mm long). Its corolla lobes lack the speckled markings that appear characteristic of L. preissii (compare Fig. 5D, F) and its nectar sheath is morphologically distinct. Capsule shape may also be taxonomically informative (depressed obovoid in L. aestiva cf. ovoid in L. preissii), although few mature capsules of the latter species have been viewed. The two species are not known to overlap in distribution (refer to the notes under L. preissii).
Selected specimens examined. AustrAliA. Description. Annual herb 2-18 cm high. Glandular hairs 0.1-0.5 mm long. Stem dark red to reddish brown, sometimes paler or greenish distally, simple or branched to varying degrees with porrect or ascending lateral branches, glandular-hairy. Leaves cauline, scattered, green (occasionally tinged red) or red-purple, lamina narrowly oblanceolate to oblanceolate, elliptic or ovate, 2.5-12 mm long including the petiole, 0.5-3(-4.5) mm wide, subacute to acute or obtuse, glandular-hairy on the abaxial surface and margins. Flowers in umbels, corymbs or short racemes, 1-ca. 150 per plant; bracts narrowly oblanceolate to oblanceolate, elliptic or linear, 2-10 mm long, glandular-hairy like the leaves; pedicels 3-18 mm long, glandular-hairy. Hypanthium depressed globose, globose or ellipsoid, 0.7-1.5 mm long, 0.7-1.8 mm wide, glandular-hairy. Calyx lobes ± equal or with the anterior pair scarcely longer than the rest, 1.3-2.3 mm long, acute, moderately to sparsely glandular-hairy. Corolla bright to pale pink (rarely white) with a white throat, sometimes with two, elongated red-pink markings towards the base of each lobe near the margins; lobes evenly arranged or with the upper (posterior) ones ± paired vertically, sometimes weakly recurved, obovate or elliptic with a slender claw, rounded, scarcely apiculate or bluntly pointed, glabrous or sometimes with sparse glandular hairs abaxially; anterior lobes equal to or slightly shorter and narrower than the posterior pair, 2.5-4.5 mm long, 1.6-2.8 mm wide; posterior lobes 2.7-4.5 mm long, 1.7-3.3 mm wide; tube creamy white, 0.2-0.5 mm long, obscured by the calyx lobes, glabrous. Labellum ventral, 2-3.5 mm long including a 0.9-1.5 mm long claw; hood yellow or whitish with dark red-maroon markings, sparsely glandular-hairy abaxially, scarcely papillate adaxially along the margins, papillate abaxially with a short, blunt, dark pink-red or sometimes yellow appendage at the cleft apex; basal appendages yellowish or white, rounded, 0.4-0.6 mm long. Column sheath white or yellowish, glabrous, 1.3-2.5 mm high on the posterior side with a thickened rim and broad anterior cleft, 3 pendulous appendages present on the inner surface towards the throat. Column creamy white, free, erect, slightly thickened distally, 2-4 mm long; stigmatic lobes to ca. 1 mm long, incurved, the lower-most developing while the column is hooded, the uppermost developing later. Capsule globose or ovoid, 1-2.3 mm long excluding calyx lobes. Seeds 0.4-0.5 mm long, 0.25-0.3 mm wide.
Diagnostic features. Levenhookia stipitata has glandular-hairy stems, bracts and calyx lobes, long pedicels (3-18 mm), a short corolla tube (obscured by the calyx lobes), a small, blunt, papillate appendage at the tip of the labellum, and a prominent column sheath (more than half the length of column). The corolla lobes may have a pair of elongated markings near the base (see notes below).
Phenology. Flowering from September to December; fruits have been collected from late October to December.
Distribution. This species is widespread in Western Australia (Fig. 7A), occurring in all bioregions within the South-West Province as well as the adjacent Yalgoo and Coolgardie bioregions. It has a more restricted distribution in South Australia where it is mostly confined to the Eyre Peninsula between Pinkawillinie Conservation Park and Point Boston, with an outlying record from the central Yorke Peninsula.
Habitat. Levenhookia stipitata grows in sand, sandy loam or clayey sand over limestone or laterite, more rarely in association with granite outcropping, usually on plains and hill-slopes but sometimes in depressions or seasonally damp habitats. Associated vegetation is varied and includes heathland, woodland, Eucalyptus marginata and Corymbia calophylla forest, Banksia, E. wandoo or E. cladocalyx woodland, open mallee woodland or shrubland, and Acacia or Melaleuca tall shrubland.
Conservation status. This common species is not considered to be under threat (IUCN (2012): Least Concern); however, in South Australia, it is listed as Rare (Schedule 9) under the National Parks and Wildlife Act 1972 (Government of South Australia 2018).
Etymology. From the Latin stipitatus (stipitate, provided with a stipe or little stalk), presumably with reference to the corolla segments. Vernacular name. Common Stylewort (Erickson 1958).  Description. Annual herb 3-12 cm high. Glandular hairs 0.1-0.2 mm long. Stem dark reddish brown, often paler distally, simple or branched to varying degrees with spreading to almost patent or ascending branches, somewhat sparsely glandular-hairy (especially towards the base). Leaves cauline, scattered, green or reddish brown; lamina narrowly oblanceolate to ± linear, elliptic or ovate, 2.5-15 mm long including the petiole, 0.5-2 mm wide, obtuse, sparsely glandular-hairy on the abaxial surface and margins towards the base. Flowers usually in umbels or corymbs or more rarely in short racemes, 1-ca. 150 per plant; bracts narrowly oblanceolate, lanceolate or ± linear, 2.5-11 mm long, glabrous or sparsely glandular-hairy like the leaves; pedicels 3-20 mm long, sparsely glandular-hairy. Hypanthium depressed globose or globose, 0.7-1.3 mm long, 0.7-1.5 mm wide, glandular-hairy. Calyx lobes ± equal or subequal (with the anterior pair scarcely longer than the rest), 1.2-2 mm long, acute or subacute, glabrous or sparsely glandular-hairy near the base. Corolla bright to pale pink (rarely white) with two, dark red-pink, ± elliptic markings near the base of each lobe (rarely faint or lacking?) and a creamy white throat, whitish on the reverse with mottled pink-red markings; lobes evenly arranged or with the upper (posterior) ones ± paired vertically, often weakly recurved, obovate with an attenuate base, glabrous or with a few glandular hairs abaxially near the base; anterior lobes slightly shorter and narrower than the posterior pair, 3.2-5 mm long, 1.5-3 mm wide, rounded or more rarely retuse; posterior lobes 3.5-5.2 mm long, 2-3.5 mm wide, rounded or bluntly pointed; tube creamy white, 0.2-0.4 mm long, obscured by the calyx lobes, glabrous. Labellum ventral, 2.5-3.7 mm long including a 1-2 mm long claw; hood dark red-maroon adaxially, pink abaxially and deep yellow near the cleft, sometimes prominently papillate, with a short, blunt point at the cleft apex, sparsely glandularhairy abaxially; basal appendages yellowish or creamy white, rounded, 0.5-0.6 mm long. Column sheath white or yellowish, glabrous, 1.2-1.8 mm high on the posterior side with a thickened rim and broad anterior cleft, 3 pendulous appendages present on the inner surface of the sheath towards the throat. Column creamy white, free, erect, slightly thickened distally, 3-4 mm long; stigmatic lobes to ca. 1.4 mm long, incurved, the lowermost developing while the column is hooded, the uppermost developing later. Capsule globose or ovoid, 1.5-2 mm long excluding calyx lobes. Seeds 0.4-0.5 mm long, ca. 0.3 mm wide.
Diagnostic features. Levenhookia octomaculata has sparsely glandular-hairy stems (especially towards the base), bracts and calyx lobes that are glabrous or sparsely glandular-hairy near the base, long pedicels (5-20 mm), a short corolla tube (obscured by the calyx lobes), and a column sheath that is usually up to half the length of the column. The corolla lobes usually have a pair of ± elliptic markings near the base and may be mottled markings on the undersurface (but see notes below).
Phenology. Flowering in October and November; fruiting in November and December.
Distribution. Levenhookia octomaculata is endemic to south-western Australia (Fig. 7C) where it is scattered across the Geraldton Sandplains, northern Avon Wheatbelt and northern Swan Coastal Plain bioregions, occurring from Eurardy Station in the north to the Chittering area in the south and extending into the Yalgoo bioregion at Mt Gibson Station.
Habitat. This species grows in sand or sandy loam, usually over limestone or sandstone but sometimes in association with granite outcropping, lateritic gravel or banded ironstone. Associated vegetation is varied and includes heath, mallee heath, Acacia and Calothamnus low shrubland, Allocasuarina campestris shrubland, Melaleuca scrub, and open woodland with Eucalyptus loxophleba or Melaleuca preissiana. It can grow in sympatry with L. stipitata.
Conservation status. Levenhookia octomaculata occurs in several nature reserves and national parks where it can be locally abundant. It is not currently considered to be at risk (IUCN (2012): Least Concern).
Etymology. From the Latin octo-(eight-) and maculatus (spotted): a reference to the pair of markings near the base of each corolla lobe. Vernacular name. Dotted Stylewort (Erickson and Willis 1956). Notes. Levenhookia octomaculata was named on account of the eight prominent markings in the throat of the flower which, at the time, were thought to be unique in the genus (Erickson and Willis 1956: 133); however, eight throat markings are present in many populations of L. stipitata which has led to a degree of taxonomic confusion. Moreover, is not known whether all populations of L. octomaculata possess eight throat markings; photographs associated with G. Byrne 600 (PERTH 06908349) suggest that they may sometimes be faint or perhaps altogether lacking. Levenhookia octomaculata can be reliably separated from L. stipitata by its bracts, which are glabrous or sparsely glandular-hairy abaxially near the base (cf. glandular hairy on the abaxial surface and margins) and calyx lobes, which are glabrous or sparsely glandular-hairy near the base (cf. moderately to sparsely glandular-hairy). It also tends to have fewer hairs on the stem and pedicels, a shorter column sheath (up to half the length of the column cf. more than half the length of the column) and a more prominently papillate labellum hood. I have observed both species growing intermixed without hybridisation at a site in Beekeepers Nature Reserve (J.A. Wege 2074 and J.A. Wege 2075), at which time 7.5 mm long, 2-3.8 mm wide; tube white, 0.5-1.5 mm long, shorter than the calyx lobes, glabrous or with a few glandular hairs distally. Labellum ventral, 4-6.5 mm long including a 1-1.5 mm long claw; hood pink with purplish maroon markings, sparsely glandular-hairy abaxially, papillae absent; appendage at the cleft apex pink with a yellow or white base, 1.8-3.5 mm long, incised or emarginate, glabrous; basal appendages oblong-clavate, 0.8-1.2 mm long, revolute distally, white with a yellow, papillate tip. Column sheath white, glabrous, 0.5-0.7 mm high with a thickened rim on the posterior side and 3 pendulous appendages on the inner surface towards the throat. Column whitish tipped pale pink, free, slender, 2.5-3.8 mm long, glabrous; stigmatic lobes to 1.5 mm long, incurved, the lowermost developing while the column is hooded, the uppermost developing later. Capsule depressed globose to globose or ovoid, 1.5-3 mm long excluding calyx lobes. Seeds 0.5-0.8 mm long, 0.3-0.4 mm wide.
Diagnostic features. Levenhookia chippendalei has a glandular-hairy stem that is usually much-branched at the base, leaves that are clustered at the base and scattered along the stems, long pedicels (5-30 mm), a short corolla tube (obscured by the calyx lobes), and a prominent, incised or emarginate appendage at the tip of the labellum. A well-developed tap root is usually evident.
Phenology. Flowering and fruiting from May to October, depending on seasonal conditions. Distribution. Levenhookia chippendalei is widespread in the arid zone in Western Australia and the Northern Territory (Fig. 7E), occurring from near Meekatharra to the Dulcie Range, north-east of Alice Springs.
Habitat. Levenhookia chippendalei grows on sandplains or sand dunes or near salt lakes and seasonal swamps, in sand or sandy clay or in gravelly soils near waterholes or creeklines. Associated vegetation includes Acacia shrubland or woodland, spinifex grassland, open low scrub with Aluta maisonneuvei and scattered emergent Brachychiton gregorii, Acacia aneura and Eucalyptus gamophylla, and Grevillea integrifolia or Melaleuca tall shrubland. It may grow in sympatry with Stylidium desertorum Carlquist, which has similarly bright pink flowers.
Conservation status. A widespread species that is not considered to be under threat (IUCN (2012): Least Concern).
Etymology. Honours George Chippendale (1921-2010, who made the earliest collection of this taxon while based in Alice Springs as the Northern Territory's first resident taxonomist.