The rediscovery of the Great Winterberg endemic Lotononis harveyi B.–E.van Wyk after 147 years, and notes on the poorly known Amathole endemic Macowania revoluta Oliv. (southern Great Escarpment, South Africa)

Abstract South Africa’s 800 km-long southern Great Escarpment hosts numerous endemic plant species only known from their type specimens or from very few records. This is a legacy of a 100–150 year lag between the pioneer work of 19th century botanists and repeat fieldwork in the 21st century. As a result, population and ecological data are lacking for many local endemic species. Here we report on the rediscovery of Lotononis harveyi B.–E.van Wyk 147 years after its original description, and provide the first detailed ecological notes on the poorly known shrub Macowania revoluta Oliv. Both species are locally endemic to the Great Winterberg–Amatholes (Eastern Cape Province). With only six known individuals, Lotononis harveyi is recommended the conservation status of Critically Endangered, with fire (and potentially grazing) being the main population constraints. Macowania revoluta is locally abundant, and it is surprising that it has been so poorly collected in recent decades. It occupies an important local niche as a keystone montane wetland species, and its narrow distribution range – combined with pressure from woody alien invasive species – suggests that its conservation status should be Rare. The research further highlights the need for continued biodiversity field research along South Africa’s poorly explored Great Escarpment.


Introduction
Th e 'Cape Midlands Escarpment' (comprising the Sneeuberg, Great Winterberg-Amatholes (GWA) and Stormberg, mostly in the Eastern Cape Province, South Africa) has been part of a southern Great Escarpment biodiversity research focus since 2005 (Clark 2010. Despite the numerous rediscoveries and species new to science (Goldblatt and Manning 2007, Nordenstam et al. 2009, Stirton et al. 2012, Boatwright and Manning 2013, Rourke et al. 2014, Clark et al. 2015, several endemic plant species only known from their type specimens have remained elusive, and the ecology of several others is still very poorly known. For instance, Clark et al. (2014) indicate that eight (23%) of the c.36 plant species endemic to the GWA are still only known from their type specimens.
Here we provide detailed notes on two of these poorly-known GWA endemics: Lotononis harveyi B.-E.van Wyk, rediscovered 147 years after its description in Flora Capensis, and fi rst-time population and ecological data for Macowania revoluta Oliv., last reliably collected some 40 years ago. Fig. 1; Plate 1

Remarks. Described by William Harvey in Flora Capensis as Buchenroedera spicata
Harv. in 1862 (Harvey and Sonder 1862), this species was collected (without date) by Mrs Elizabeth Mary Barber sometime in the 1800s on the 'Winterberg'. Th ree vouchers of this original material exist: one in the Bolus Herbarium (BOL), under her own initials; one in Kew (K) under F.W. Barber, her husband's initials; and one in Trinity College Dublin Herbarium (TCD), also under her own initials. At the time of Van Wyk's (1991) 'Synopsis of the genus Lotononis', this species was still only known from the type material. Th is remained the case when Clark et al. (2014) published their overview of plant diversity and endemism in the GWA.
Extensive fi eldwork by VRC in the Great Winterberg in January 2009 for his PhD resulted in the fi rst recollection of this species since its publication in Flora Capensis, although this was not realised at the time. Th e specimen (Clark VR,Pienaar C,Daniels R 316; GRA, NBG) was given the tentative identifi cation L. cf. viminea (E.Mey.) B.-E.van Wyk until re-examination in 2014 suggested that it was in fact L. harveyi. A follow-up expedition to fi nd more plants was undertaken on the 6 th November 2014, Th e 2009 site (hereafter Locality 1) was relocated without diffi culty, and the search extended southwards down the 19 th century wagon trail to the trigonomic beacon and eastwards to the edge of Paradise Kloof (part of the Fenella Falls gorge complex), covering approximately one square kilometre. Despite exploring the area carefully (in the plateau grassland and along the edge of the ravine, as well as in the fynbos and grassland on the steep slopes of the ravine) only six individual plants were found (three in fl ower, three not).
Key characters confi rming rediscovery. Th e 2009 specimen was assigned to L. harveyi on the basis of the elongated racemes (therefore not L. trichodes (E.Mey.) B.-E. van Wyk, another local Great Winterberg endemic); the white fl owers with densely hairy petals (based on the label information and a few remaining petals on the specimen, as the plant was mostly in pod); the long calyx lobes, hirsute leaves, and long stipules (which match Van Wyk's 1991 fi gure 89 very well). Th e identifi cation was confi rmed by the November 2014 plants, especially by the white, hairy petals.
Population assessment. Th e plants at the three localities are described separately: In 2009, two plants were found and collected at Locality 1, recorded as ca. 50 cm tall and with white fl owers. Th is site occupies two square meters and is located on the two meter-wide 'middle man' between the 19 th century wagon trail over the Great Winterberg and the current Finella Falls farm access road. In November 2014, at the same site, three plants were found. One was 45-50 cm tall, branched and in full fl ower. Th e other two were 15 cm and 5 cm tall respectively, both damaged on their main axes (probably being the two specimens collected in 2009, one lodged in the Selmar Schonland Herbarium, GRA, and a duplicate to the Compton Herbarium, NBG) but shooting side branches; neither were fl owering. Locality 2, situated on the western lip of Paradise Kloof, comprised one plant 15 cm tall, in fl ower. Locality 3, only a little further back from Locality 2, contained two plants: one 30 cm tall, in fl ower, the other 20 cm tall, not in fl ower.
Habit and ecology. Van Wyk (1991) indicated that the habit of L. harveyi was not known. From the recent collections it can now be stated that it is an erect to spreading woody shrublet 20-50 cm tall, comparing well with Mrs Barber's notes on her TCD voucher: 'about a foot and a half high -slender with very few branches -perennial'. As was postulated by Van Wyk (1991), it is indeed distinct from the prostrate habit of L. trichodes. Mrs Barber notes on her TCD voucher 'blossoms in autumn', and as we found the species in full bloom in November, L. harveyi perhaps fl owers in sync with the bimodal rainfall regime dominant in this area, i.e. early and late summer (Mucina and Rutherford 2006).
If the two smaller plants recorded in November 2014 at Locality 1 are indeed the survivors of the two 2009 vouchers, their limited growth since then suggests that the species grows extremely slowly, and this may partly account for its apparent rarity. In contrast, it is surprising that there is no obvious evidence of recruitment despite the fl oribund infl orescences.
Habitat. Generally speaking, L. harveyi occurs in Amathole Montane Grassland (Mucina and Rutherford 2006). Th e habitat conditions at each locality are discussed separately to identify common ecological factors which may account for this species' apparent rarity.
Locality 1 consists of a very small area of moribund Th emeda triandra Forssk. grassland. Other species present in this area are Cliff ortia sp. (50-60 cm tall), Luzula africana Drège ex Steud. and Fingerhuthia sesleriiformis Nees. Th e remainder of the road reserve comprises the invasive tree Populus × canescens (Aiton) Sm.. Th e soil is deep and clayey. No plants were evident in the grassland on either side of the road reserve: these grasslands comprise well-gazed Th emeda triandra grassland studded with tall Festuca costata Nees tussocks. Th e gradients are gentle, soils deep and rich, there is limited rockiness, and the grass is probably burnt on a regular basis to limit the spread of the unpalatable Festuca costata.
Mrs Barber's TCD voucher notes that her specimens grew 'amongst the rocks and long grass' and in 'good soil'. Th is -together with the six plants all being found in fi re-exclusion areas or moribund grassland -suggests that the species is susceptible to fi re and possibly grazing pressure. Th ere is no currently no indication on whether this species is a resprouter or a reseeder, and research into the autecology of this species is warranted.
Conservation status and threats. Lotononis harveyi is currently listed as Data Defi cient (Victor and Dold 2005). Based on our observations we suggest that it be considered 'Critically Endangered' until more surveys in the general area are carried out. Currently virtually nothing about its biology is known, and accordingly no concrete conservation recommendations can be made. Possible general threats are the over-use of fi re (a fi re management history of the relevant farms can probably be obtained to indicate fi re frequency), although fi re has been a natural part of the ecology of these mountains well prior to the discovery of this species.
Th e general area is vulnerable to invasion by Rosa rubiginosa L. (a fast-emerging invader, with several seen in Localities 1 & 3) and Pinus patula Schltdl. & Cham. (Locality 2), while Locality 1 is in danger of being overrun by Populus × canescens. Th e targeting of mountain environments for wind farms in South Africa is another concern, with potentially detrimental impacts on localised endemics such as L. harveyi.
Areas for further exploration. A more exhaustive search along the rugged, extensive rocky rims of the Fenella Gorge area and perhaps on the (still unexplored) slopes of Mount Frederick and Besterskop (the promontory below the main Great Winterberg peak) and the scarp slopes below Th e Ruitjies might produce more plants. In fact, much of this area has still to be explored botanically, particularly from Mount Frederick-Besterskop eastwards along the scarp below Th e Ruitjies. Th e relevant localities/properties are summarised as follows (taken from 1:50 000 sheet 3226AD Spring Valley): Finella Falls 1 (parts of this farm were well surveyed in 2009, but there are extensive rocky areas not yet explored); the scarp margins on the Bosch River Spruit 26; Petraea 2 (being the south-western slopes of Mount Frederick and Besterskop); Oribi Fountains 3 (also being the south-eastern slopes of Mount Frederick and Besterskop, as well as the south-facing scarp of Th e Ruitjies); and those portions of Emerald Hill 26 and adjacent farms that comprise the 'Groenberg'.

Macowania revoluta Oliv. (Asteraceae)
Remarks. Macowania revoluta, the type species of Macowania, was fi rst collected by Peter MacOwan in the eastern part of the Amatholes sometime prior to 1870 and described by Daniel Oliver in Icones Plantarum (Hooker 1867(Hooker -1871. Th is almost exclusively southern African genus was later revised by Smith (1927). Relatively few collections of M. revoluta exist (most specimens being repeat collections by a few historical collectors, see below). Raimondo (2008) indicates that this species had not been re-collected since before 1949, although herbarium investigations by JB indicate that there is one collection from 1976 (albeit with virtually no other data). Th e fi rst concrete records of this species' continued existence was a collection in July 2010 by JB and Nicola Bergh (Compton Herbarium) in the vicinity of Keiskammahoek (Locality 1 -the closest record to the type locality), followed by a second specimen in October 2010 by APD near the Madonna & Child Waterfall in Hogsback (Locality 2). Following this, in December 2014, the species was found by VRC to be abundant in the central Amathole mountains along the Amatola Hiking Trail (Localities 3-5). In March 2015 another plant was recorded by VZ from Isidenge State Forest on the road to Evelyn Hut (one of the overnight huts on the Amatola Hiking Trail; Locality 6).
Key characters confi rming rediscovery. Th e plant is typically an erect, candelabra-like shrub 50 cm to three metres tall, but often lax and weedy when small. Th e leaves are distinctly linear, dark green, sticky glandular and sweetly aromatic with strongly revolute margins (hence its specifi c name) and a raised abaxial midrib. Both disc and ray fl orets are yellow, with the ray fl oret petals rounded upwards. Th e involucre is bell-shaped with distinctly long bracts; the margins are strikingly dark-brown.
Another species endemic to the GWA, Arrowsmithia styphelioides -earlier believed by Hilliard and Burtt (1985) to be closely affi liated to Macowania -has since been Plate 2. Th e poorly known Great Winterberg-Amatholes endemic Macowania revoluta Oliv. A a capitulum showing the distinctive dark involucral bract margins (Bentley J 1) B shrubby, candelabra growthhabit (above Wolf River Main Forest along the Amathole Hiking Trail, specimen not collected) C detail of fl owering stem (Bentley J 1) D young plant showing ruderal tendencies (Clark VR 451). found by recent phylogenetic analysis to be nested within Macowania, as sister to M. revoluta (Bentley et al. 2014; the taxonomic revision is currently in progress). Arrowsmithia styphelioides diff ers in its sharply acuminate, ovate leaves, absence of the raised abaxial midrib, as well as in several features of the reproductive organs. Otherwise, no other Macowania species are currently known from the GWA (Clark et al. 2014), with the next closest known population of another species (M. pulvinaris N.E.Br.) being on the Andriesberg, 115 km to the north.
Population assessment. At Locality 1, M. revoluta was found to be locally abundant, with plants in excess of one meter in height and forming the dominant species. Only one plant was noted at Locality 2, growing on the edges of a derelict Pinus patula plantation and Acacia mearnsii De Wild. invasions. Locality 3 contained about 20 plants, 0.5-1 m tall, with two in fl ower and many others in seed. Locality 4 comprised a large colony (ca. 50 m × 100 m in extent) with M. revoluta (1-3 m tall) forming the dominant species; many were in fl ower. Locality 5 consisted of a dense but small colony (1-3 m tall) covering ca. 50 m × 10 m; also with many in fl ower. Only one plant was located at Locality 6, and was not in fl ower.
Habitat and ecology. Based on the information on the type material, Clark et al. (2014) suggested that this species should be looked for along forest edge and in adjacent grassland. Th is was a good deduction, as the plants form dense colonies on wet scarp slopes, on cliff -tops, on the margins of indigenous forests, and on the edges of pine plantations and alien thickets. Macowania revoluta generally prefers wet areas, and can form the dominant component of mountain fynbos in suitable habitat, co-occurring with various Cyperaceae, Erica species, Pelargonium cordifolium (Cav.) Curtis, Psoralea glabra E.Mey., Pteridium aquilinum (L.) Kuhn subsp. aquilinum, Rubus rigidus and Widdringtonia nodifl ora (L.) Powrie.
Conservation status and threats. Macowania revoluta is currently listed as Data Defi cient (Raimondo 2008), but is obviously much more common than previously thought. Despite the species' local abundance, its ruderal tendencies, and being somewhat tolerant of less dense alien vegetation, it is (mostly) known from one quarter degree grid on a small mountain range that is under severe pressure from woody alien invasive species (notably Acacia dealbata Link, A. mearnsii, A. melanoxylon R.Br. and Pinus patula). Furthermore, the potential impacts of climate change on this (and other local montane endemics) is currently unknown. Also, it's response to fi re (and autecology in general) is unknown and requires investigation. Accordingly we recommend the status 'Rare'.
Recommended areas for further exploration. Macowania revoluta potentially occurs anywhere along the wet southern scarp of the Amathole Mountains, between Katberg Pass and Stutterheim. So far it has not been recorded on the adjacent Great Winterberg.
Historical collections and localities (a selection of these is mapped in Figure 1). South Africa, Eastern Cape Province, 3227CA & 3227CD, Amathole Mountains (King Williams Town): rocky summit of Pirie Mountain, Buff elsrivier, Kaff raria (label detail diff ers among the duplicates). October 1887 (this date on the GRA specimen is a bit of an enigma, as it post-dates the species description). Macowan P 2013 (BOL, E, GH, GRA, K, NYBG, P, PRE; type specimens).