Journal of Threatened Taxa | www.threatenedtaxa.org | 26
November 2019 | 11(14): 14914–14916
Crepidium aphyllum (Orchidaceae), a new record from Bhutan
Kinley Rabgay 1 & Pankaj Kumar 2
1 Senior Forest
Ranger, Trashigang Forest Division, Department of
Forest and Park Services, Ministry of Agriculture and Forests, Royal Government
of Bhutan.
2 Kadoorie Farm and Botanical Garden, Lam Kam Road, Lam Tsuen, Tai Po, New Territories, Hong Kong S.A.R., P.R.
China.
1 knlyrbg@gmail.com,
2 sahanipankaj@gmail.com (corresponding author)
doi: https://doi.org/10.11609/jott.5017.11.14.14914-14916
Editor: Anonymity
requested. Date of publication:
26 November 2019 (online & print)
Manuscript details: #5017 | Received 14 October 2019
| Final received 25 October 2019 | Finally accepted 29 October 2019
Citation: Rabgay, K. & P. Kumar (2019). Crepidium aphyllum (Orchidaceae), a new record
from Bhutan. Journal of Threatened Taxa 11(14): 14914–14916. https://doi.org/10.11609/jott.5017.11.14.14914-14916
Copyright: © Rabgay & Kumar 2019. Creative Commons Attribution 4.0 International
License. JoTT
allows unrestricted use, reproduction, and distribution of this article in any
medium by adequate credit to the author(s) and the source of publication.
Funding: None.
Competing interests: The authors declare no competing
interests.
Acknowledgements: Authors would like to express their gratitude to Mr. Karma Leki (Chief Forestry Officer) and colleagues of Trashigang Forest Division, Eastern Bhutan for their
support and encouragement to the first author in studying orchids in the wild.
The generic name Crepidium Bl.
is derived from the Greek ‘krepidion’,
which means “little boot” referring to the saccate base of labellum (Blume
1825; Pridgeon et al. 2006). It is a large genus containing 280–292
species distributed from tropical and subtropical Asia to the Pacific region (Pridgeon et al. 2006; Govaerts et
al. 2019). Of these, four Crepidium species are known to occur in Bhutan: C.
acuminatum (D.Don) Szlach.—listed as Malaxis
acuminata (Pearce & Cribb 2002); C. khasianum (Hook.f.) Szlach. and C. purpureum (Lindl.)
Szlach.—listed as Malaxis
khasiana and M. purpurea
(Gurung 2006), and C. josephianum (Rchb.f.) Marg. (National Biodiversity Centre 2017).
During a recent field exploration in 2019, the first
author discovered a few scattered plants of an unidentified leafless orchid
growing along with another orchid, Anthogonium
gracile Wall. ex Lindl. on moss and soil covered
rock outcrops. The observation was made
at moist oak forest (1,565m elevation) in Galing, Shongphu Gewog, Trashigang
District, eastern Bhutan. After a
careful investigation of the collected materials (i.e., plants and flowers), it
was identified as C. aphyllum (King & Pantl.) A.N.Rao by the second
author. Crepidium
aphyllum is a new record for the Bhutanese orchid
flora, and with this record the number of species under this genus goes up to
five in Bhutan. A brief description of
the plant and its biology is presented with photographs. A voucher specimen has been deposited at
National Herbarium Center, Thimphu,
Bhutan for future reference.
Enumeration of the species
Crepidium aphyllum (King & Pantl.) A.N.
Rao
J. Orchid Soc. India. 14: 65 (2000)
Malaxis aphylla (King & Pantl.) T.Tang & F.T.Wang in Acta Phytotax. Sin.
1: 71 (1951).
Microstylis aphylla King & Pantl. in Ann. Roy. Bot. Gard. (Calcutta) 8: 18, t.22
(1898).
Type: India, Sikkim, Teesta Valley, 305m, 11 July
1896, Pantling No. 455 (K000387669)
(K!).
Small leafless, probably partly-mycoheterotrophic,
terrestrial or lithophytic herb, 7–15 cm tall,
bearing flowers on the upper 1/3rd of the inflorescence. Roots very short and very few,
vermiform. Pseudobulbs or corms,
cylindric-ovate with irregular surface, erect or slightly inclined, white,
rough surfaced, 1.0–2.5 cm long, 0.5–0.8 cm wide. Scape arising from apex of subterranean
pseudobulbs or corms, sheathed towards the lower end with 3–5 scarious scales.
Inflorescence racemose, open flowers laxly placed, buds (unopened)
densely placed. Pedicel and ovary
1.6–2.0 mm long, 0.3mm wide, ribbed.
Floral bracts lanceolate, deflexed, acuminate, 1.0–2.0 mm long, 0.5mm
wide. Flowers shield-like, facing
forward, non-resupinate, coloured uniformly in pale-yellow with dull purple
towards edges, glabrous, 3.0–5.2 mm long, 1.5–2.5 mm
wide; dorsal sepal ovate-oblong, erect, sub-obtuse, yellow tinted with
reddish-brown, glabrous, margin curved backwards
1.5–1.8 mm long, 0.5–1.0 mm wide; lateral sepals obovate, sub-obtuse, margin
entire, yellowish-green tinted with reddish-brown, reflexed backwards, 0.8–1.2
mm long, 0.2–0.3 mm wide; petals falcate or sickle shaped, placed close to the
lateral sepals, acute, margin entire, yellowish-green, 0.8–0.2 mm long, 0.5mm
wide; lip ovate, acute, margin entire, no constriction between midlobe and side lobes, concave, with a linear cavity lined
with glands on the margin, yellowish-green, 2.3–2.6 mm long, 1.5–1.8mm wide;
side lobes falcate, adpressed on the dorsal sepal,
acute, margin entire, 0.7–1.0 mm long, 0.1–0.3 mm wide; column short,
quadrangular, apically lobed with two stelidia, ca.
0.6mm long, 0.4mm wide. Mature fruits
clavate, ribbed, 0.6–0.7 mm long, 1.2–1.4 mm wide.
Flowering: June–July.
Habitat: Plants were found growing in litter on moss covered
rock outcrops in a moist deciduous Oak Quercus griffithii
forest.
Specimens examined: India, Sikkim, Teesta Valley, 305m, 11.vii.1896, Pantling No. 455 (P00404840) (P!-isotype). Bhutan, Galing, Trashigang Forest
Division, 11.viii.2019, K. Rabgay 20190711-01 (THIM).
Global conservation assessment: Crepidium aphyllum was previously considered to be endemic to
India with distributions in Arunachal Pradesh, Sikkim and West Bengal (King
& Pantling 1898; Chowdhery
1998; Lucksom 2007; Rao 2010; Sherpa et al. 2018; Govaerts et al. 2019) until its recent discovery in China
(Fan et al. 2012). Hence it is an
addition to the orchid flora of Bhutan.
This is a very rare species, which is evident from the fact that the
only specimens existing across the online herbaria of the world are the type
and isotypes of Pantling collected almost 123 years
ago., There is, however, a possibility
of finding a specimen of this species at some non-online herbaria in
India. There is not even a single
digital image of this species available on google search except for the
painting from King & Pantling (1898). The current sighting of C. aphyllum in Bhutan comprised only five mature
plants. Based on GeoCAT
(Moat 2007), the extent of occurrence is estimated as 29,310.577km2
and area of occupancy as 20km2.
The total number of mature individuals seen in Bhutan was six, and the
poor representation of the image on social media also points towards its
rarity. Fan et al. (2012) already
assessed this species as Critically Endangered globally, which seemed to be
incorrect due to the occurrence of this species in at least two countries and
four locations. With this rate of
encounter the estimated number of mature individuals throughout its
distribution range including the five known current locations cannot be more
than 500. In this whole area, there is a
major threat of habitat degradation due to forest loss. This is a partial mycoheterotrophic
plant which are very specific to its mycorrhizal symbiosis and hence to their
habitats (Jacquemyn et al. 2016). Based on current information, previous
assessment and following IUCN Standards and Petitions Committee (2019)
guidelines, this can be assessed as Vulnerable (VU-D2).
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