Journal of Threatened Taxa | www.threatenedtaxa.org
| 26 January 2021 | 13(1): 17592–17596
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.6393.13.1.17592-17596
#6393 | Received 11 July 2020 | Final
received 04 October 2020 | Finally accepted 07 January 2021
Bulbophyllum spathulatum (Orchidaceae),
a new record for Bhutan
Pema Zangpo
1, Phub Gyeltshen 2 & Pankaj Kumar 3
1 Gomphu Range Office, Royal Manas National Park, Department of Forest and Park
Services, MoAF, Gelephu,
Bhutan.
2 Bumthang Forest Division, Department of
Forest and Park Services, MoAF, Trongsa, Bhutan.
3 Kadoorie Farm and Botanic Garden, Lam Kam
Road, Lam Tsuen, Tai Po, New Territories, Hong Kong S.A.R., P.R. China.
1 pemazangpo611@gmail.com, 2 gyeltshenforest@gmail.com,
3 pkumar@kfbg.org (corresponding author)
Editor: Anonymity
requested. Date of publication:
26 January 2021 (online & print)
Citation: Zangpo,
P., P. Gyeltshen & P. Kumar (2021). Bulbophyllum spathulatum (Orchidaceae),
a new record for Bhutan. Journal of Threatened Taxa 13(1): 17592–17596. https://doi.org/10.11609/jott.6393.13.1.17592-17596
Copyright: © Zangpo
et al. 2021. Creative Commons Attribution
4.0 International License. JoTT allows unrestricted use, reproduction, and
distribution of this article in any medium by providing adequate credit to the
author(s) and the source of publication.
Funding: Self funded.
Competing interests: The authors
declare no competing interests.
Acknowledgements: We express our sincere gratitude
to Director General of Department of Forest and Park Services; Mr. Samten Wangchuk, Chief Forestry Officer and staff of Royal Manas National Park motivation and encouragement. Authors
also extend thanks to Mr. Sangay Tshewang
of Jigme Singye Wangchuck
National Park for sharing information about the distribution of B. spathulatum in Wangdue
Dzongkhag.
Bulbophyllum Thouars (1822) is one of the largest
genera in family Orchidaceae comprising approximately
2,200 species, distributed in the tropical and subtropical regions of the world
with the richest diversity in the tropics of Africa and Asia (Pearce &
Cribb 2002; Chen & Vermeulen 2009; Chase et al. 2015; Gyeltshen
et al. 2020). In Bhutan, the genus is
represented by 57 species from 13 sections distributed mostly in eastern,
western, and southern parts of Bhutan (Gurung 2006; Dalstrom
et al. 2017; Gyeltshen et al. 2020).
During a recent floristic
exploration in the Subrang and Pantang
under Zhemgang District in 2019, the first author
encountered a small population of an unfamiliar orchid growing on a tree. For initial examination sufficient
photographs were taken. After critical
examination of morphological parts, careful scrutiny of herbarium materials and
literatures (Reichenbach 1970; Seidenfaden 1970,
1973; Garay et al. 1994; Pearce & Cribb 2002;
Chen & Vermeulen 2009; Averyanov 2016), this
species was identified as Bulbophyllum spathulatum (Rolfe ex E.Cooper)
Seidenf. and this is a new record for Bhutan (Figure
1).
Originally described as Cirrhopetalum spathulatum
Rolfe ex E.W.Cooper, this species was circumscribed
under the genus Bulbophyllum by Seidenfaden (1970) as Bulbophyllum
spathulatum.
Alternatively, Garay et al. (1994) described a
new genus as Rhytionanthos where based on
fusion of lateral sepals to form a synsepal by inward
twisting and connation of their edges and included Bulbophyllum
spathulatum as Rhytionanthos
spathulata, however, this concept has
changed. The genus Rhytionanthos
has now been merged under Bulbophyllum (Pridgeon et al. 2014) and accordingly followed thereafter (Govaerts et al. 2020).
Bulbophyllum spathulatum
had been
included in the Orchids of Bhutan by Pearce & Cribb (2002) based on its
occurrence in adjacent areas in India, however, it was never collected from
within the political boundaries of Bhutan.
Hence, the present collection of the species from Zhemgang
District, Bhutan stands as a new record for Bhutan. Later, plants were also discovered at one
more area in Zhemgang District followed by two sites
in Wangduephodrang District, however, no voucher
specimens were collected due to the rarity of the species. Detailed morphological descriptions, updated
distribution, phenology, and ecology along with distribution map and colour
photographs are provided based on the collected specimens.
Bulbophyllum spathulatum
(Rolfe ex.
Cooper) Seidenf. Bot. Tidsskr.
65: 347 (1970); Cirrhopetalum spathulatum Rolfe ex. Cooper in Orchid Rev. 37: 106
(1929); Rhytionanthos spathulatum
(Rolfe ex Cooper) Garay, Hemer
& Siegerist in Nordic J. Bot. 14(6): 639 (1994).
Type: Thailand, Bangkok, Roebelen 292-12 (K000829943) (K!-Holotype).
Epiphytic herb. Roots terete, ca. 1mm thick, caespitose.
Rhizome creeping, terete, 2.5–9.3 cm long, 1.5–3.0 mm wide, covered with
membranous sheaths, old sheaths brownish, new sheaths greenish-yellow with
purplish-mauve spotted, 1.0–1.5 cm long, 1.0–1.2 cm wide, persistent,
internodes of rhizome 1.0–1.4 cm long.
Pseudobulbs cylindrical-ovoid, narrowly-ovoid, 1.5–4.0 cm x 0.6–1.5 cm
wide, 2.5–9.3 cm apart from each other on the rhizome, glabrous,
greenish-yellow, brownish-pale yellow with the age, longitudinal ridges
present, bearing a solitary leaf at the apex.
Leaf blade green, linear-oblong to oblong-elliptic, 3.5–15.0 cm long,
1.3–2.5 cm wide, entire, apex sub-acute or obtuse, base attenuate, adaxially glabrous, abaxially whitish-brown spotted and occasionally
purple coloured, fleshy, coriaceous to leathery. Petiole yellowish-green, 0.4–1.0 cm long, ca.
0.2 cm wide, longitudinally channeled, glabrous, obliquely notched on the pseudobulb,
conduplicate. Inflorescences arising
from the base of the pseudobulbs, sub-umbellate, ca. 6.5–7.0 cm long, 4–10
flowers, erect; peduncle with 4–5 sheaths, 1.5–2.5 cm long, pale yellow with
mauve streaks and spotted towards apex, sheathing bracts broadly ovoid to
oblong-ovoid, 0.8–1.2 cm x 0.7–0.9 cm wide, thin, glabrous,
basal bracts turning brownish with the age.
Flowers, 4.2–5.0 cm long including pedicel and ovary, resupinate,
golden-yellow with reddish-brown spotted.
Floral bracts oblong–lanceolate, 10–14 × 4–5 mm, thin, margin entire,
apex acute, base truncate, glabrous, whitish-pink,
three-veined. Pedicel and ovary pale
yellow with reddish-maroon spots, 1.5–2.5 cm long, 1.5–2.0 mm wide. Dorsal sepals obovate, 7.5–9.0 × 4.0–4.5 mm
when flattened, yellowish-green with reddish-brown spots mostly in the middle,
two prominent reddish spots at the base, margin entire, apex obtuse and
slightly mucronate, base truncate, abaxially glabrous,
adaxially papillose, concave, three-veined.
Lateral sepals fused to form slipper-shape, 1.6–2.2 cm long, 5.5–6.5 mm
wide, upper and lower edges connate to forming a synsepal;
synsepal 10–11 mm wide, golden-yellow with
reddish-brown, outer surface minutely warty with white papillae including
margins, apex rounded and slightly incurved, base obliquely truncate to rounded
when dissected, two prominent reddish-maroon spots at base. Petals oblong to oblong-lanceolate, 4.0–5.0 ×
1.2–2.0 mm, yellow with deep maroon-purplish, falcate towards left, slightly
incurved, margin entire, revolute, apex
obtuse, base obliquely truncate, surface glaucous, left petal slightly longer
than the right petal. Lip thick and fleshy, ovate–lanceolate, 4–4.2 mm long,
1.5–2.0 mm wide, glabrous, side ridges present,
margin entire, mobile, recurved, base with reddish-brown and yellow towards the
apex, apex obtuse, base broad, truncate to slightly auriculate. Column yellow, quadrangular, 1.8–2.0 mm long,
2mm wide, forwarded and incurved foot; foot rectangular, 2.0–2.5 mm long, 1.5mm
wide, purplish-maroon, minutely wing margins with maroon lining, margin entire,
prominent triangular shape at abaxial surface, column wall with prominent
deep-maroon lines one on each sides separating the column wing, a swollen
protruding structure at the inter-connecting inner column and column foot
bases. Stelidia
deltoid, ca. 1mm long 1.5mm wide, yellow.
Operculum sub-spherical, cucullate, ca. 1.4–1.6 mm long, 1.0–1.2 mm
wide, white towards the base from middle and yellowish-green towards the
apex. Pollinia four in two pairs, ovoid,
ca. 1.2 × 1.0 mm, glaucous, slightly flat and slightly curved towards apex from
the middle. Fruits yellowish–green, clavate, 2.5–2.7 cm long, 1.5–1.7 cm wide,
straight or slightly curved, longitudinally grooved (Figures 1; Image 1, 2).
Phenology: Flowers from
mid-February to end of March, fruits mature from May to September.
Habitat: Bulbophyllum
spathulatum was found growing as epiphyte on the
tree trunks of Canarium strictum
in the subtropical forest at around 350m along the river bank. Other associated trees and shrubs in its
habitat comprises of Tetrameles nudiflora R.Br., Ficus
auriculata Lour., Maesa
chisia Buch.-Ham. ex D.Don.,
Terminalia grandiflora Benth., Alangium alpinum (C.BClarke) Smith. & Cave, Alstonia
neriifolia D.Don.,
Celastrus paniculatus
Willd and Boemeria
sp. The associated orchids sharing
the same habitat are Dendrolirium lasiopetalum (Willd.) Chen
& Wood and Vanda ampullacea (Roxb.) L.M. Gardiner.
Updated Global distribution:
Bhutan, China, India, Myanmar, Laos, Thailand, and Vietnam.
Specimens examined: Vietnam: 2
(P00355148) (P!), 01.i.1954, Annam, Dalat, Vietnam,
C.R.S.T. 274; (P00355149) (P!), 01.i.1957, Annam, Dalat,
Vietnam, Grillet s.n.;
(P00355150) (MNHN-P!), 1,000m, Region de Dalat, Pougour, Vietnam, P. Tixier s.n.. Thailand: 0916 (K000597358) (K!), 23.ii.1931, 1,000m,
Pu Kio, Chaiyapum, Thailand, A.F.G. Kerr 292;
(K000829943) (K!), 10.i.1973, Thailand, C. Roebelen s.n. India: 131
(BM000516930) (NHMUK!), northern Sikkim, Sikkim, India, 01.iii.1891, R. Pantling 131; (P00355147) (P!), 01.iii.1891, tropical
valleys, India, R. Pantling s.n.;
(L1488962) (NBC!), Sikkim, India, R. Pantling s.n. Bhutan: 015–016
(THIM), Subrang, Trong, Zhemgang District, 20.ii.2020, 1,130m, P. Zangpo & P. Gyeltshen 017.
For figure
& images - - click here
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