Two new Phlegmariurus species (Lycopodiaceae) and one new combination from Peninsular Malaysia

Abstract Two new species, Phlegmariurus iminii Kiew (Lycopodiaceae) from limestone karst and P. monticola Kiew from montane habitats, are described from Peninsular Malaysia and a new combination is made for Phlegmariurus pinifolius (Trevis.) Kiew. Phlegmariurus iminii, known from a single hill threatened by quarrying, is Critically Endangered; while P. monticola and P. pinifolius that are relatively widespread are of Least Concern.


Introduction
The last published flora account of Lycopodiaceae for Peninsular Malaysian with keys and species descriptions was that of Ridley (1919) who recorded 13 species. The most recent reliable checklist (Parris and Latiff 1997) listed 12 species. At the generic level, molecular studies show that Lycopodium L. s.l. is paraphyletic (Wikström and Kenrick 2001;Field et al. 2016) and should be divided into 16 monophyletic genera (PPG I 2016) of which Diphasiastrum Holub, Huperzia Bernh., Lycopodiastrum Holub, Lycopodium L., Palhinhaea Franco & Vasc., Pseudodiphasium Holub and Pseudolycopodiella Holub are each represented by a single species in Peninsular Malaysia and Phlegmariurus Holub, which is more diverse, has 12 species including the two new species described below, bringing the total for the family to 19 species.
Revision of the family currently underway for the Flora of Peninsular Malaysia and the focus of botanical exploration by the Flora of Peninsular Malaysia team (Kiew and Rafidah 2007) have brought to light two new species of Phlegmariurus, one an epiphyte on trees growing on limestone; the other an epiphyte on trees in lower to upper montane forest.

Materials and methods
Specimens of all Peninsular Malaysian Phlegmariurus species and those of the surrounding region (Thailand, Sumatra and Borneo) in the herbaria at BM, K, KEP, KLU and UKMB (acronyms follow Thiers et al. 2017, continuously updated) were examined. Type material was examined in these herbaria as were type images relevant to this study available on JSTOR Global Plants website (http://jstor.org). Literature relevant to the region (West Malesia and Thailand), including protocols, were consulted. Conventional methods employed in herbarium taxonomy were applied in this study. All measurements were taken from dried herbarium specimens. Photographic documentation was taken from living specimens in their natural habitat. Provisional conservation assessments follow the guidelines in IUCN (2012) and Chua (2010). Description. Medium-sized, tufted epiphyte. Stems lax, pendulous, ca. 30 cm long, slender, terete, ca. 2.5-3 mm in diameter; branching dichotomously 4 times, branches equal. Leaves spaced 3-4 mm apart, arranged in two alternating subspiral whorls of three, ascending at ca. 40° to stem, sessile; lamina dark green, thin and papery, lanceolate, (7-)10 × 1.8-2 mm, base flat, cuneate, margin flat, entire, narrowed to a minutely apiculate apex, glabrous above and beneath; midrib distinct on both surfaces, prominent above, keeled beneath. Strobilus slender ca. 1 mm thick, branched once dichotomously near the base with a short stalk 8-14 mm long and branches ca. 20 mm long followed by a short 50-90 mm long section of stem with sterile leaves, terminating in a strobilus (20-)40-70 mm long. Sporophylls distinct from leaves, spaced along the axis, sessile, ovate, much smaller than leaves, 1.5-2 × 0.75-1 mm, keeled on outer surface, base rounded and concave around the sporangium, margin entire, apex acute. Sporangium broadly reniform, ca. 2 mm long and wide, creamy becoming yellow when mature. Spores isotetrahedral with convex margins, polar axis ca. 20 µm, distal surface minutely foveolate. Diagnosis. This new species belongs to the Phlegmariurus phlegmaria group of species in being a medium-sized epiphyte with pendent stems, flat leaves broadest at base with a distinct midrib and sporophylls much smaller than vegetative leaves. Amongst Peninsular Malaysian species, it is different from P. phlegmaria (L.) T.Sen & U.Sen and P. salvinioides in its narrower, sessile leaves, 7-9 × 1.8-2 mm, positioned at 40° to the stem (vs. broader, subpetiolate leaves 5-15 × 2-5.5 mm, perpendicular to the stem) and in its unbranched strobili (vs. much branched). While the distinction between P. phlegmaria and P. salvinioides (Herter) Ching tends to intergrade, P. iminii is distinct without any specimens of these two species resembling it. It is similar to P. pinifolius (Trevis.) Kiew in its narrow, sessile leaves but its leaves are less crowded and positioned at 40° to the stem (vs. crowded and perpendicular to the stem) and its strobili are short and unbranched (vs. long and branched from the base). It also superficially resembles P. banayanicus (Herter) A.R. Field & Bostok from the Philippines but that species has broader leaves narrowed to the base (usually 8-10 × 2-3 mm) that are perpendicular to the stem and has branched inflorescences. Phlegmariurus iminii is distinct from all these species by a combination of its narrow, sessile leaves positioned at 40° to the stem and its straight, short, unbranched strobili with sporophylls that are not strongly appressed to the stem (Table 1).

Phlegmariurus iminii
Distribution. In Peninsular Malaysia, it is at present known only from the type locality, Pahang, Merapoh District, Gua Gunting. Ashley R. Field (pers. comm.) notes that the species is a target for plant collectors and it is in cultivation from parts of Thailand and other parts of Peninsular Malaysia from a variety of habitats, although we have not been able to locate it in commercial nurseries in Malaysia.
Provisional conservation status. Critically Endangered (A1d, B2ab [iii,v]). Its only confirmed locality is a single karst limestone hill that lies outside the network of Totally Protected Areas and has been threatened by quarrying for cement and is surrounded by oil palm plantations that expose it to disturbance from agricultural activities, in particular by the practice of clearing vegetation by burning. The limestone flora occupies only 0.4% of land area but is biodiverse harbouring at least 14% of the Peninsula's vascular flora (Chin 1977), so it is particularly vulnerable to disturbance (Kiew 1997). In addition, many of its species like Phlegmariurus iminii are known from less than five limestone hills (Kiew et al. 2017).
Ecology. The type specimen grew on a tree on a steep slope, slightly shaded near the summit of a limestone karst hill.

Phlegmariurus monticola
Diagnosis. It belongs to the Phlegmariurus squarrosus group in that its sporophylls are similar in shape, although smaller, than the leaves. Phlegmariurus monticola is immediately distinct from P. squarrosus (G.Forst.) Á.Löve & D.Löve s.l. that in Peninsular Malaysia is morphologically relatively uniform by a combination of its tufted, shorter stems 11-32.5 cm long (vs. single-stemmed at the base and (20-)40-55(-200) cm long), leaf midrib obscure above and prominent beneath (not distinct above and faint beneath), strobili more slender ca. 3 mm wide, that are in pairs and usually branch dichotomously once or twice (vs. strobili 4-5 mm wide, single and always unbranched). In addition, their distributions do not overlap; P. squarrosus is a lowland species grow- ing on trees usually at less than 300 m elevation, while P. monticola is a montane species occurring at 1400-2100 m elevation. It also superficially resembles P. prolifera (Blume) A.R Field & Bostok in its slender strobili ca. 3 mm wide and sporophylls arranged in four rows, but it differs in its shorter, narrower leaves (8-10 × 0.75-1.5 mm (vs. leaves 10-15 × 1.5-2 mm) and its narrowly lanceolate sporophylls 0.5-1 mm wide (vs. triangular-ovate sporophylls 1.5-2 mm wide).
Distribution. Peninsular Malaysia (Kelantan, Perak and Pahang). Provisional conservation status. Least Concern. It is found in most accessible montane areas in the Main Range suggesting that it is likely to be more widespread. The montane forest above 1000 m is protected because of the restriction on clearing forest on steep slopes. However, this does not apply to hill resorts where forest is cleared for resort infrastructure and at Cameron Highlands for vegetable and flower farms (Kiew 1997). However, its populations need to be monitored because it is for sale in nurseries in Malaysia, Singapore and Thailand (AR Field, pers. comm.) so collecting of plants from the wild may become a threat.
Ecology. In Peninsular Malaysia, in light shade usually in lower montane forest, sometimes in upper montane forest, at 1400-2100 m elevation.
Etymology. Latin, monticola -dweller in mountains. Notes. In appearance, it is immediately distinct from P. squarrosus in being less robust, in being tufted with up to 7 stems, having shorter stems that are only about twice the length of the strobili and leaves with the midrib obscure above and prominent beneath; while Peninsular Malaysian individuals of P. squarrosus have single stems (not tufted) that are longer so their strobili are about a fifth or less the length of the stem and the leaf midrib is distinct above and faint beneath.

New combination
Lycopodium pinifolium Blume (1828: 264) was described and recorded to occur from Malaya to Papua, but it was not until 1984 that this species appeared in Malaysian publications (as Huperzia pinifolia Trevis.) when it was recorded from the Gunung Mulu National Park, Sarawak (Parris et al. 1984) where it was keyed out with Huperzia phlegmaria and distinguished from that species by its linear-lanceolate leaves at least six times longer than broad with a cuneate base and by its sporophylls with acuminate tips that protrude beyond the sporangia. A detailed account described and illustrated this species (Johns 1991) based on specimens from Gunung Mulu grown in the Royal Botanic Gardens Kew. However, it was not until Parris and Latiff (1997) listed it that it appeared in Peninsular Malaysian publications. However, its identity became confused when subsequent publications illustrated different species under this name. For example, that of Aziz-Bidin (2002, figs. 10, 11) illustrated P. tetrastichus and that of Noraini et al. (2010, figs. 47, 48) figured P. squarrosus. Names on herbaria specimens were similarly in a muddle. A full description is therefore provided below.
The name Lycopodium pinifolium Blume was an illegitimate name because it had earlier been used for an African species by Kaulfuss (1824). In 1874, Trevisan described Huperzia pinifolia Trevis. as a new name: in fact he was conscious of the illegitimacy of the name of Blume because of the (older) name of Kaulfuss. In this case (International Code of Nomenclature, art. 7.4 (ICN 2012)) the new name is typified by the type of the replaced synonym. Blume (1828), in describing his species, recognised varieties B, C and D but for varieties C and D he noted '(an species?)' implying that there was doubt that they belonged to this species. Specimens representing these varieties were all annotated by his hand, the labels noting only 'Java' without recording a collector, locality or date. The specimen annotated as var. C (barcode L 0057377) is closely similar to P. proliferus (Blume) A.R.Field & Bostock and does not belong to P. pinifolius and the specimen representing var. D is a piece too small to identify with certainty. The other two specimens both belong to P. pinifolius in their habit (relatively short dichotomously branching stems with dense, narrowly lanceolate leaves perpendicular to the stem) and the abruptly distinct, straight strobili. The typical variety (barcode L 0057375) has strobili that are branched dichotomously while var. B (barcode L0057376) has unbranched strobili, which represent an earlier stage in the growth of the strobili, which eventually branch. The herbarium sheet with barcode L 0057375 is here selected as the lectotype because it best represents a mature plant of this species. Type. Java. Without collector, number, date or precise locality (lectotype here selected: L!, electronic image with barcode L 0057375).
Distribution. Thailand, Peninsular Malaysia, Java, Borneo (Sabah and Sarawak), the Philippines, Indonesia (Sumatra to New Guinea). Hassler (2018) also records it from Sri Lanka, Vanuatu and the Solomon Islands. In Peninsular Malaysia, collected from Penang, Perak, Kelantan and Pahang.
Provisional conservation status. Least Concern. Ecology. Not common, in upper hill dipterocarp to lower montane forest, in light shade, on trees on hill sides at 800-1250 m altitude.
Etymology. Latin, -folius = leaf; referring to the similarity to leaves of Pinus.
reviewers, Drs Ashley Field and Jaideep Mazumdar for their insightful comments that have greatly improved the manuscript and to Mohamad Aidil Noordin for the botanical plates. We are indebted to the curators of the herbaria in BM, K, KLU, SING and UKMB for permission to examine specimens in their care.