趙明旭，董洪進(jìn)，尹志堅，楊子誠，孫鴻雁，唐芳林

(國家林業(yè)局昆明勘察設(shè)計院，昆明 650216)

PlatantheraRichard is one of the largest genera in the tribe Orchideae (Orchidaceae) comprising 123 species[1-2], and is one of the largest terrestrial genera in the tribe Orchideae. Most species are distributed across Asia and North America; few species extend into Europe, North Africa, and Central America[2-11].

There are 42Platantheraspecies recorded inFloraofChina[9], but the taxonomy of these species is controversial[12]. Over the past nine years, a series of new species and new records in China have been published[12-21]. Based on recent molecular evidence, some species placed in the generaHerminiumandPeristyluswere transferred toPlatanthera, and some species previous placed inPlatantherawere moved to other genera[2, 22-23]. For example,H.orbiculareHook.f. was treated asP.orbicularis(Hook.f.) X.H. Jin, Schuit. et Raskoti, whileP.latilabrisLindl. was treated asH.latilabre(Lindl.) X. H. Jin, Schuit., Raskoti et L. Q. Huan. Currently, with the literature records, there are at least 65 species ofPlatantherain China.

Almost all species ofPlatantheraare terrestrial, but a few, such asP.dulongensisX. H. Jin et Efimov,P.sikkimensis(J. D. Hooker) Kraenzlin,P.ophiocephala(W. W. Smith) T. Tang et F. T. Wang, andP.stenantha(J. D. Hooker) So, occasionally grow as epiphytes on tree trunks. The habitat of epiphyticPlatantheraspecies is restricted to tree trunks or large lower branches where a thick layer of humus or moss is present[2].

During fieldwork conducted in November 2017 in Menglian County, Yunnan Province, SW China, an epiphyticPlatantheraspecies with blooming flowers growing in a cluster ofOtochilussp. on a tree caught our attention (Fig. 1. A). After careful identification based on the available literature[2, 9, 24-25], we confirmed the species asPlatantheraangustilabrisSeidenf., which is a new record of this species in China. Note that this is not the speciesP.angustilabris(King & Pantl.) X. H. Jin, Schuit. et W. T. Jin, an illegitimate name transferred fromHerminiumangustilabreKing et Pantl.[15, 22], which was corrected asP.angustilabre(King et Pantl.) X. H. Jin, Schuit. et W. T. Jin in Zhouetal. (2016)’s recent publication[11].

窄唇舌唇蘭(新擬，F(xiàn)ig.1 A-E)

PlatantheraangustilabrisSeidenf. 1995. Opera Botanica 124: 11. 1995. Type: THAILAND. Doi Inthanond, near irrigation station no. 1, 20 October 1988,Thaithong511 (Holotype: C, in spirit), Isotypes: (K, Photo ! [barcode no. K-000796974], available from: http://www.orchidspecies.com/platangustilabris.htm).

Description: Plants are 10-20 cm tall. Rootstock tuberous, fusiform, (2-4) × (0.5-1) cm, densely covered with hair. Stem erect, with 2-3 tubular sheaths at base, 1-3 leaved. Leaves usually linear to narrowly-oblanceolate, sessile, (4.1-15) × (0.8-4.1) cm, base clasping, apex acute to acuminate. Peduncle robust, with several scattered, foliaceous, ovate-oblong to linear-lanceolate bracts, (0.8-3.8) × (0.35-1.4) cm, lowermost bract longer than the flower. Inflorescence 2-15 flowered, lax to dense. Flowers yellowish green. Tepals 6-12 mm long, 3-5 nerved, margins smooth, upper tepals distinctly spreading. Dorsal sepal broadly cordate-triangular, rounded to subacute, (5.4-9) × (6.5-9.5) mm; lateral sepals falcately lanceolate and twisted, apex obtuse to subacute, (8-12) × (2.9-4.5) mm. Petals very obliquely ovate-lanceolate, (6.5-9) × (3.8-5.7) mm. Lip (10-16) × (2.8-4.5) mm, almost linear, apex obtuse to acute; spur 15-25 mm long, slightly incurved, gradually tapering toward apex, directed ± downwards. Column 5-6 mm long, with concave stigmatic surface, lateral stigma lobes much smaller than the median lobe. Anther locules distant from one another, upper parts nearly parallel and diverging downwards, with the distance between them 2-3 mm in the upper and 3-4 mm in the lower half of the anther. Pollinarium ca. 4 mm long, caudicle ca. 2.5 mm long, viscidium broadly ovate to suborbicular. Ovary 9-17 mm. Capsule not seen.

Flowering: October to December.

Distribution: Myanmar, Thailand, Vietnam, and China.

Newlocality: Hemo Village, Mengma Township, Menglian County, Pu’er Prefecture, Yunnan Province (E 99°20′49.71″ N 22°10′1.98″, 云南省孟連縣勐馬鎮(zhèn)臘福大黑山賀莫村附近).

HabitatandEcology: Epiphytic on trees in mid-montane moist evergreen broad-leaved forests, 2 145 m above sea level.

Specimensexamined:PlatantherasinicaTang et F. T. Wang, (PE!, [barcode no. PE-01997882]);P.sikkimensis(Hook.f.) Kraenzl., (PE!, [barcode no. PE-01451863]);P.angustilabrisSeidenf. Isotypes: (K, Photo! [barcode no. K-000796974]).

A. Habit; B. Inflorescence; C. Front view of flower; D. Rootstock; E. Side view of flower. Photographed by M. X. Zhao on 4th, November, 2017 during the fieldwork. Platanthera angustilabris Seidenf. is very similar to P. sikkimensis from the Himalayas. The main difference is that P. angustilabris Seidenf. has narrowly-lanceolate leaves up to 15 cm long, whereas P. angustilabris has shorter lanceolate leaves (up to 7 cm long)Fig.1 Platanthera angustilabris Seidenf

Acknowledgments: We are grateful to the anonymous reviewer’s critical comments. We thank Zhang Tianxing, Yang Wenjie, and other staff from China Forest Exploration & Design Institute in Kunming for organizing and coordinating work during the investigation. We are sincerely grateful to Tan Yunhong of Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences for the help in identification. Also, the authors thank all of the participating staff from Menglian Forestry Bureau, Menglian Environmental Protection Bureau, and Forest Rangers from Lafu, Hemo, and Dongnai Villages.