THAI FOR. BULL. (BOT.) 43: 74–78. 2015. Pleocnemia conjugata (Dryopteridaceae), a new record for Thailand RATSAMEE SIMMA1, SUMON MASUTHON2 & STUART LINDSAY3 ABSTRACT. Pleocnemia conjugata (Blume) C.Presl, a new record for Thailand, is described and illustrated. KEY WORDS: Dryopteridaceae, fern, new record, Pleocnemia conjugata, Tectariaceae, Thailand. INTRODUCTION In May 2005 and June 2007 several speci- mens of an interesting but unfamiliar Pleocnemia Until recently, the fern genus Pleocnemia species were collected in Khao Pu Khao Ya C.Presl was thought to be represented in Thailand National Park, Phatthalung province. Subsequent by only three species, P. hemiteliiformis (Racib.) herbarium and library research revealed this Holttum, P. irregularis (C.Presl) Holttum and P. species to be Pleocnemia conjugata (Blume) submembranacea (Hayata) Tagawa & K.Iwats. These C.Presl. As this is a new record for Thailand, the were treated under Dryopteridaceae in the Flora of key to Pleocnemia given in the Flora of Thailand Thailand (Tagawa & Iwatsuki, 1988) and under needs to be amended and a thorough description Tectariaceae by Lindsay et al. (2009). However, the needs to be provided. recent phylogenetic work of Liu et al. (2014) supports their retention in Dryopteridaceae. AMENDED KEY TO THE SPECIES OF PLEOCNEMIA IN THAILAND 1. Frond bipinnatifi d or bipinnate, sori without indusia 2. Frond bipinnatifi d; veins copiously anastomosing to form areoles other than costal and costular ones P. irregularis 2. Frond bipinnate; veins anastomosing to form costal and costular areoles only, or rarely with one more row of areoles 3. Base of pinnules not widened; no glands on sporangia P. hemiteliiformis 3. Base of pinnules conspicuously widened; glands present on sporangia P. submembranacea 1. Frond tripinnate (at base), sori with indusia P. conjugata DESCRIPTION Males., Ser. II, Pterid. vol. 2, part 1: 16, fi gs 4a & 4b. 1991.— Aspidium conjugatum Blume, Enum. Pleocnemia conjugata (Blume) C.Presl, Epimel. Pl. Javae 2: 169. 1828. Type: Indonesia, Moluccas, Bot.: 259. 1851 [‘1849’]; Holttum, Reinwardtia 1: s.d., Blume s.n. (K! 000420778, L?). See notes below 177, fi gs. 1, 5, 7 & 9. 1951; Holttum, Rev. Fl. and Holttum (1955) for further discussion of the Malaya 2: 534, fi gs. 314 & 315. 1955 [‘1954’]; type. See Holttum (1991) for additional synonyms. Molesworth Allen, Gard. Bull. Sing. 17: 268. 1959; Figs. 1 & 2. Holttum, Kew Bulletin 29: 350. 1974; Piggott, Terrestrial. Rhizome short, stout, erect or Ferns Malaysia in Colour: 330. 1988; Holttum, Fl. decumbent, the apex appearing woolly due to a dense 1 Field and Renewable Energy Crops Research Institute, Department of Agriculture, Chatuchak, Bangkok 10900, Thailand. E-mail: [email protected] 2 Department of Botany, Faculty of Science, Kasetsart University, Chatuchak, Bangkok 10900, Thailand. 3 Gardens by the Bay, 18 Marina Gardens Drive, Singapore 018953. E-mail: [email protected] SW 8736-p074-078-G8.indd 74 12/1/58 BE 9:51 PM PLEOCNEMIA CONJUGATA (DRYOPTERIDACEAE), A NEW RECORD FOR THAILAND (R. SIMMA, S. MASUTHON & S. LINDSAY) 75 covering of very long, soft, linear scales. Scales irregularly shaped areoles on each side of the mid- basally attached (although rather loosely so), up to veins of the lobes but usually only in the basal part 25 mm long and 0.8 mm wide (at the base, less than of the lobes, the more distal veins being free, 0.1 mm wide above the base), concolorous brown forked once or twice. Indumentum: the midveins of or reddish-brown, margins coarsely toothed. Stipe the lobes and some veinlets bearing oblong, unicel- to ca 115 cm long, densely scaly at base (with lular, translucent-yellow, glandular hairs below, scales similar to those on the rhizome), glabrous or without such hairs above. Veinlets sometimes also apparently so above the base (with a goodd micro- bearing very sparse, fi ne, transparent, patent, uni- scope, sparse, small, appressed, scales can sometimes seriate glandular hairs below, without such hairs be seen). Stipe slightly fl attened above, not grooved above. Costae and costules bearing numerous in fresh material (but often grooved when dry), transparent, patent, uniseriate hairs below. Costae reddish-brown at base and below for its entire densely covered with similar but shorter hairs length, green above. Lamina tripinnate, deltoid- above. Costules glabrous above. Rachis glabrous ovate in outline, up to ca 120 cm long and ca 125 or sparsely hairy below (with or without sparse, cm wide, green and slightly shiny above, much small, appressed scales similar to those on the paler and not shiny below, subcoriaceous. Rachis stipe), sparsely or densely hairy above. Sori round, similar to stipe, reddish-brown below, at least in dorsal on veinlets, mostly medial (midway between lower part, green above, not grooved when fresh. the midvein and margin of each fertile lobe), some Pinnae up to ca 17 pairs of free pinnae consisting supramedial (slightly closer to the margin than to (from the base upwards) of one pair of tripinnate the midvein of each fertile lobe), indusiate, indusia pinnae, up to 4 pairs of widely-spaced bipinnate round-reniform, glabrous, persistent, usually folded pinnae, and up to 15 pairs of pinnatifi d or more in half at maturity. Sporangia long-stalked, glabrous. shallowly-lobed pinnae. The basal pinnae or supra- Sorall paraphyses absent. Spores monolete, bilateral, basal pinnae usually the longest or the lowermost 2 bean-shaped with winged perispore. or 3 pairs of pinnae more-or-less the same length. Thailand.— PENINSULAR: Phatthalung [Si Basal pinnae up to ca 70 cm long and 45 cm wide, Banphot District, Khao Pu Khao Ya National Park, long-stalked (to 6.5 cm), refl exed, asymmetrically Riang Thong Waterfall, 180 m, 12 May 2005, triangular due to several enlarged basiscopic pinnules, Simma et al. 190 (BKF, 2 specimens); same locality, the fi rst (basal) basiscopic pinnule pinnate, to 35 cm 20 June 2007, Simma & Kaeowkhao 288 (BK, long and 8.5 cm wide, the second (and sometimes BKF, SING); same locality, 20 June 2007, Simma third) basiscopic pinnules always absent. Suprabasal & Kaeowkhao 294 (BKF)]. and other large bipinnate pinnae up to ca 70 cm long and 25 cm wide, shortly stalked or sessile, not Distribution.— Southern Myanmar, Malaysia refl exed, oblong or lanceolate, base truncate, apex (Peninsular, Sabah, Sarawak), Singapore, Indonesia acuminate, with 14–17(–20) pairs of free pinnules (Kalimantan, Java, Sumatra, Sulawesi, Lesser before the pinnatifi d apex. Pinnules (excluding Sunda Islands, Moluccas), Philippines, Papua New those of the basal pinnae), sessile, angled at about Guinea (Holttum, 1974). Records from Hong Kong 60 degrees to the costae, the largest ca 6–10(–13) (e.g. Holttum, 1991) were misidentifi cations for cm long × 1.3–1.8 (–2.3) cm wide, somewhat oblong, other Pleocnemia species. base truncate, apex acuminate, the margins lobed Ecology.— Pleocnemia conjugata is a large to a little more than half way to costule. Lobes 4–6 terrestrial fern. In Thailand, it grows on the banks mm wide, falcate, apex rounded or blunt, margins of a stream in evergreen forest at an altitude of 180 toothed distally. Each pair of lobes separated by a m. In Peninsular Malaysia, it grows in semi-shade narrow sinus, a short blunt tooth-like structure at in lowland dipterocarp forest and hill dipterocarp the base of each sinus (projecting from the dorsal forest up to 560 m altitude (Jaman & Latiff, 1999). surface of the lamina before being pressed). Veins Throughout its range it appears to have a preference distinct on both surfaces, veinlets anastomosing to for lightly shaded or rather open forest and, according form long costular areoles (between the midveins to Holttum (1955), “it certainly does not occur in of the lobes) and a few irregularly shaped areoles normal fully shaded primitive forest”. Holttum (1991) between the costules and the sinuses; a few additional also concluded that P. conjugata grows in places SW 8736-p074-078-G8.indd 75 12/1/58 BE 9:51 PM 76 THAI FOREST BULLETIN (BOTANY) 43 with a short regular dry season but its discovery in it are costae, the axes arising from costae are cos- Pulau Tioman and Singapore (since 1991) indicates tules and the axes arising from the costules are (in that it is capable of growing in aseasonal forests. this species which has lobes not pinnulets) the mid- Proposed IUCN conservation assessment.— veins of the pinnule lobes. Least Concern (LC). This species is widespread (4) Although the basal pinna illustrated in with a large AOO and EOO and with no known Figure 1 was drawn from Simma et al. 190, both of uses leading to discernable threats. the duplicates at BKF now, unfortunately, lack Notes.— (1) The indumentum of Pleocnemia their basal pinnae. The most complete specimens conjugata is somewhat variable across its range. are Simma & Kaeowkhao 294 (BKF) and Simma & All plants are characterized by the presence of at Kaeowkhao 288 (BKF, SING). least some unicellular translucent-yellow glandular hairs below (at least when fresh; often discoloured, ACKNOWLEDGEMENTS damaged or destroyed by alcohol and/or drying) and We thank Mr Somchai Saeongkaeo and Mrs transparent uniseriate hairs on many axes above Phloenchit Pawangsawat, Khao Pu Khao Ya and/or below. However, the density and distribution National Park for their advice, support and facilities of these hairs is somewhat variable (e.g. Singaporean during this study, and Miss Rawadee Kaewkaw plants have yellow glandular hairs on the costae [spelt ‘Kaeowkhao’ on the specimen labels] for her and costules as well as on the midveins of the lobes assistance in the fi eld. We also thank the directors and veinlets; and the costae, costules and rachises and curators of BCU, BK, BKF, PSU and SING for have no uniseriate hairs below). The description of providing access to their specimens.