Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 January 2022 | 14(1): 20523–20525
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.6377.14.1.20523-20525
#6377 | Received 09
July 2020 | Final received 13 November 2020 | Finally accepted 22 December 2021
Robiquetia gracilis (Lindl.)
Garay—a new record to the flora of Anamalai Hills, Tamil Nadu, India
B. Subbaiyan
1, V. Ganesan 2, P.R. Nimal Kumar
3 & S. Thangaraj
Panneerselvam 4
1 Anamalai Tiger Reserve Forest Pollachi,
Tamil Nadu, India.
2 Coimbatore, Tamil Nadu, India.
3 Orchid Conservationist, Plantart Botanic Private Limited, Coimbatore, Tamil Nadu,
India.
4 Anamalai Tiger Reserve Forest Pollachi,
Tamil Nadu, India.
1 bsubbaiyan@gmail.com
(corresponding author), 2 ganesanifs93@gmail.com (corresponding
author), 3 nk@plantart.in, 4 stpselephant@gmail.com
Editor: Anonymity
requested. Date of publication:
26 January 2022 (online & print)
Citation: Subbaiyan,
B., V. Ganesan, P.R.N. Kumar & S.T. Panneerselvam
(2022). Robiquetia
gracilis (Lindl.) Garay—a new record to the flora of Anamalai
Hills, Tamil Nadu, India. Journal of
Threatened Taxa 14(1): 20523–20525. https://doi.org/10.11609/jott.6377.14.1.20523-20525
Copyright: © Subbaiyan et al. 2022. 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: Our sincere thanks are due to
Botanical Survey of India, Southern Regional Center
Coimbatore, for permitting us to consult the herbarium and library, and the
Tamil Nadu State Forest Department for providing the opportunity to conduct the
survey of plants in the Anamalai Tiger Reserve.
Robiquetia, an indispensable genus of the family Orchidaceae, was first described by Gaudichaud-Beaupréin,
1829 in his work “Voyage autour du monde”; it belongs to the tribe Vandeae. It encompasses about 70 species which are
distributed from India and Sri Lanka to Samoa (Cootes
2011; Ormerod 2017). In India, the genus
is represented by four species (Robiquetia gracilis, R. jossephiana,
R. spathulata, and R. succisa), of which Robiquetia
jossephiana is known to be endemic to
Kerala (Kumar & Manilal 1992, 1994; Jalal &
Jayanthi 2012).
Anamalai Tiger Reserve (ATR) is carved out of the Tamil
Nadu portion of the Anamalais. It lies south of the
Palakkad gap in the southern Western Ghats mountain chain. Geographically, it
is located between the longitudes 76.821–77.356E and latitudes 10.220–10.555N.
The two important UNESCO World Heritage Sites of Western Ghats such as the Karian Shola and the Grass hills are located within the
ATR.
Frequent
field surveys by the authors (2017–2019) in Anamalai
hills has resulted in locating a number of rare and unknown species of plants
which included a specimen of an interesting orchid species of the genus Robiquetia. Specimens were collected from two
localities in Valparai plateau and were kept at Anamalai orchidarium for monitoring, on initiation of the
inflorescence, the authors visited the site and observed the flowering and
fruiting and recorded the same. A detailed taxonomic study with perusal of
relevant literature (Kumar & Manilal 1994; Sasidharan 2013) and consultation with experts confirmed
its identity as Robiquetia gracilis, a rare species, till now not reported
from the Anamalai hills. In Tamil Nadu this species
was reported in Kakachi-Kodayar, Kalakkad-Mundathurai
Tiger Reserve (KMTR; Ganesan & Livingstone 2001) and Athirumala
and Agasthymala of Kerala (Sasidharan
2013). Based on scrutiny of the specimen, it was confirmed that the species
exists in the Anamalais ranging 1,100–1,400 m
altitude. It is a new record to the flora of Anamalai
hills. Robiquetia gracilis
can be distinguished from other species by the zig-zag and sheathed stem
character. Meanwhile, tiny white flowers with red dots confirm its
identification in the wild. Ganesan & Livingston (2001) reported the habitat of Robiquetia
gracilis as mid-elevation evergreen forest
(1,200–1,550 m) areas of KMTR.
Robiquetia gracilis
(Lindl.) Garay
Bot. Mus. Leafl.
Harvard Univ. 23: 197. 1972
Saccolabium gracile Lindl.,
Gen. Sp. Orchid. Pl. 225. 1833. (Image 1)
Monopodial,
pendulous, epiphyte. Roots: branched, terete, elongate, emerging from nodes up
to 25 cm long. Stems 10–15 cm long, semi hard, zigzag, green sheathed. Leaves
alternate 6–12 x 0.5–0.7 cm, linear-lanceolate, acuminate at apex, sheathed at
base. Inflorescence leaf opposed, drooping raceme, 8–12 cm long. Peduncles
filiform, 12–16 flowered. Flowers, white, 0.4–0.5 cm across. Sepals and petals
0.15–0.2 cm long, linear, subulate. Lip 0.3–0.4 cm long, spurred, lateral
lobes; mid-lobe small. Column 0.1–0.15 cm long; foot 0. Pollinia 2, globose,
attached to long slender caudicle. Pedicels and ovary
0.3–0.35 cm long. Capsules subglobose, 0.5 × 0.4 cm.
Habit: Grows as epiphytic herbs
in association with Garcinia morella (Gaertn.) Desr.
Habitat: Evergreen forests
between 1,100–1,400 m.
Specimens examined: India, Tamil
Nadu, Coimbatore district, Anamalai Tiger Reserve,
2018, Ganesan & Subbaiyan (0055; Image 2) Anamalai Herbarium, Pollachi.
Distribution: Southern India
(Kerala, Tamil Nadu) and Sri Lanka.
Flowering & Fruiting:
August–January.
Notes: A very few individuals of
this species were identified in the collection locality. The species has not
been recorded earlier in any localities of the reserve so far. Therefore, it is
suggested that an exploration in other possible localities is essential to
assess its exact conservation status. Two live specimens are deposited in Anamalai Orchidarium at Attakatti
for conservation purpose.
References
Cootes, J.E. (2011). Philippine Native Orchid
Species. Katha Publishing Co., Inc., Quezon City, 289pp.
Ganesan, R.
& C. Livingstone (2001). Checklist of orchids from a mid elevation
evergreen forest at Kakachi-Kodayar, Kalakkad-Mundanthurai Tiger Reserve, Agasthyamalai,
southern Western Ghats. Zoos’ Print Journal 16(3): 445–446. https://doi.org/10.11609/JoTT.ZPJ.16.3.445-6
Jalal, J.S.
& J. Jayanthi (2012). Endemic orchids of peninsular India: a review. Journal of Threatened
Taxa 4(15): 3415–3425. https://doi.org/10.11609/JoTT.o3091.3415-25
Kumar, C.S.
& K.S. Manilal (1992). Epiphytes orchids of India. Rheedea 2(2): 80–100.
Kumar, C.S.
& K.S. Manilal (1994). A Catalogue of India Orchids.
Bishen Singh Mahendra Pal
Singh, Dehradun, 84pp.
Ormerod, P.
(2017). Checklist
of Papuasian Orchids. Nature & Travel Books,
Lismore (Australia), 496pp.
Sasidharan, N. (2013). Flowering Plants of Kerala: CD-ROM ver. 2.0.
Kerala Forest Research Institute, Peechi, Kerala.