Journal of Threatened Taxa |
www.threatenedtaxa.org | 26 April 2021 | 13(5): 18385–18389
ISSN 0974-7907 (Online) | ISSN 0974-7893
(Print)
https://doi.org/10.11609/jott.6171.13.5.18385-18389
#6171 | Received 16 May 2020 | Final received
06 July 2020 | Finally accepted 02 April 2021
A new record of an
endangered and endemic rare Rein Orchid Habenaria
rariflora from Gujarat, India
Mital R. Bhatt
Department of Botany,
Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara,
Gujarat 390002, India
Editor: Anonymity requested. Date of publication: 26 April 2021
(online & print)
Citation: Bhatt, M.R. (2021). A new record of an
endangered and endemic rare Rein Orchid Habenaria
rariflora from Gujarat, India. Journal of Threatened
Taxa 13(5): 18385–18389. https://doi.org/10.11609/jott.6171.13.5.18385-18389
Copyright: © Bhatt 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 author
declares no competing interests.
Acknowledgements: The author
acknowledges the South Dangs Forest Division, Ahwa, Dangs, Gujarat for a
research grant. The author is obliged to
Dr. J.S. Jalal for the support and encouragement and Dr. Ravikiran N. Kulloli, Dr. Vinod Gosavi, and Dr. Prasad Kothareddy for providing map and photographs.
Abstract: Habenaria rariflora
A.Rich., a species endemic
to the southern and western parts of India, is reported for the first time from
Gujarat State, western India. A detailed
description and photographs are provided here for easy recognition in the
field. Further, morphology, distribution,
habitat, ecology, anatomy of leaf, rarity index, and conservation status of the
species are provided.
Keywords: Anatomy,
conservation, rarity Index, taxonomy.
The genus Habenaria, belonging to the family Orchidaceae, subfamily Orchidoideae,
tribe Orchideae, and subtribe Orchidiinae
was described by Willdenow (1805). The generic name is derived from the Latin
word “habena” means ‘a strap, holder, or
rein’, probably attributed to the thread-like fringes of the lip in the
flowers. It is one of the largest
terrestrial orchid genera with c. 885 species worldwide (Govaerts
et al. 2020). Habenaria
species are distributed in both the New and Old World tropics and subtropics,
with a few species in temperate areas, particularly in eastern India (Pridgeon et al. 2001).
The genus is terrestrial, characterised by undivided tubers, spurred
lip, short column, small & minute caudicle &
viscidium, and long & free stigma drawn out at the entrance of spur (King
& Pantling 1898; Pridgeon
et al. 2001; Dangat 2015). Habenaria is
represented by c. 62 species in India (Singh et al. 2019). So far, six species have been recorded from
Gujarat, making it the largest terrestrial genus of the family for the state
(Shah 1978; Anonymous 1996). During the
orchid survey, a remarkable species of Habenaria
was collected from Chinchali Village of Dang
District. Various morphological characters of this species did not match with
the previously documented species from Gujarat State (Suryanarayana 1968; Desai
1976; Shah 1978, 1983; Vora 1980; Raghavan et al. 1981; Reddy 1987; Bole &
Pathak 1988; Anonymous 1996; Tadvi 2014). Hence, the systematic treatment of this taxon
along with a detailed description, morphology, anatomy, photographs, ecological
notes, rarity index, and conservation status has been provided here.
Materials and Methods
Field survey and
collection
In the course of
ongoing taxonomic studies on the family Orchidaceae
in Gujarat State, an interesting but unknown species of Habenaria
was collected from Chinchali Village of the Dang
District in September 2017. The district
is located in the southeastern part of Gujarat and is
part of the Western Ghats. It lies
between 20.561–21.086N & 73.466–73.943E.
The species was collected during the flowering stage and was
photographed in its natural habitat as well as in the laboratory using various
digital cameras (Nikon Coolpix P600, Nikon 5300). Details on habit, habitat, flowering, and
fruiting period were recorded at the time of collection.
Herbarium preparation
and identification
The species was
studied for its gross morphological characters during the collection and
critically examined under stereo zoom microscope for its detailed taxonomic
identification. After a meticulous
examination of its morphology and perusal of the relevant literature, the
species was identified as Habenaria rariflora A. Rich. (Hooker 1890; Santapau
& Kapadia 1964; Abraham & Vatsala 1981; Misra 2007). The
description of vegetative and reproductive characters is based on live
plants. All the representative parts for
identification of orchids were collected and used for herbarium
preparation. The prepared herbarium
specimens were deposited at the Herbarium of The Maharaja Sayajirao University
of Baroda (BARO) and Botanical Survey of India, Arid Zone Regional Centre,
Jodhpur (BSJO).
Anatomical study
The matured and fresh
young leaf samples of H. rariflora were
fixed in FAA (Formaldehyde: acetic acid: ethanol 10: 5: 50, v/v/v) for
preservation (Berlyn et al. 1976). The fixed samples were dehydrated with a
graded series of TBA and processed for paraffin embedding (Johansen 1940; Ruzin 1999).
Transverse sections of 15–20 µm thickness were taken using Leica rotary
microtome (Leica RM 2035). The sections
were stained with Safranin-Astra blue stain combination and mounted with DPX
for permanent slide. The permanently
mounted sectors on slides were observed and all the important features were
photographed using a Leica DM1200 microscope coupled to an image capture
system.
Rarity status
analysis
Rarity index was
calculated to assign a status to the species at the regional level (Jalal
2012). A statistical formula was
developed considering five quantification parameters (Table 1). The rarity value of the species depends on
all the five quantifiable parameters as mentioned in the below formula. The data were entered into an excel
spreadsheet and summarized using descriptive statistics.
h1+s1+p1+p2+p3
R = –––––––––––––
5
Where, h1
= a number of habitats, s1 = a number of sites in Gujarat, p1 =
distribution in India, p2 = phytogeographical distribution within
the Indian subcontinent, p3 = phytogeographical distribution
globally.
The scale of rarity
index ranges from 1 to 5. Rarity ranking
(Very Rare: 0.5–1; Sparse: 1.1–2; Occasional 2.1–3; Common: >3).
Results
Taxonomic treatment
Habenaria rariflora
A. Rich. in Ann. Sci. Nat., Bot. ser. 2, 15: 70, t.
2D. 1841; Hook.f., Fl. Brit. India 6: 136.
1890; T. Cooke, Fl. Bombay 2: 716. 1907; Santapau and
Kapadia, Orchids Bombay 15, t. 3, f. 9, 10. 1966; Abraham & Vatsala, Introd. Orchids 216.
1981; Lakshmin. in B.D. Sharma et al., Fl.
Maharashtra 2: 43. 1996.
Lithophytic or terrestrial herb,
13.0–15.0 cm high with inflorescence.
Tubers 1 or 2, small, ovoid or oblong.
Leaves 3.0–5.0 × 1.1–1.8 cm, radical, oblong to lanceolate, broadly
oblong, ovate to elliptic, or even ovate.
Inflorescence 10–12 cm long, 1–4-flowered terminal racemes. Flowers 2.0–2.5 cm long, white, pedicellate,
bracteate. Bracts 1.9–2.2 × 0.7–0.8 cm, ovate to lanceolate, acute. Pedicel with ovary c 4.0cm long. Sepals subequal, subacute; dorsal sepal c 1.0
× 0.6–7.0 cm, broadly ovate; lateral sepals c 1.1 × 0.6 cm, obliquely ovate,
spreading, apical portions slightly decurved.
Petals 2-partite; upper segment 0.8–1.0 × 0.4–0.6 cm, obliquely
triangular–ovate; lower segment 1.0–1.3 cm long, filiform, acute. Lip c 1.5cm long, tripartite from a little
below middle; lateral segments scarcely 0.8–1.0 cm long, filiform or narrowly
linear to subulate; mid segment 0.8–0.9 × c 0.2 cm, linear, subobtuse.
Spur 4.5–4.6 cm long, curved, white. Column c 0.5 × 0.3 cm, oblong,
rounded, greenish-white. Pollinia
yellow, ovoid to oblong, caudicle slender. Capsules 2.0–3.0 cm long, strongly ribbed,
beaked (Image 1).
Specimen
Examined: 0208 (BSJO), 10.ix.2017, Chinchali
((20.749N & 73.933E, 1,000m), Ahwa, Dangs, Gujarat, India, coll. Mital
R. Bhatt (Image 2).
Phenology: August
(flowering) and September–October (fruiting).
Distribution: This
endemic species is reported to occur in Andhra Pradesh, Goa, Gujarat (present
report), Karnataka, Kerala, Maharashtra, and Tamil Nadu (Figure 1).
Habitat and Ecology:
The habitat is dominated by tropical moist deciduous vegetation with an
average rainfall of 2,000mm. The species
was found growing on vertical rocks and old walls along with grasses up to an
elevation of 1,000m.
Only a few
individuals were located from the site.
Anatomical study
In the transverse
section, the leaf shows a crescent shape with a minor abaxial groove in the
middle section. The cuticle is thin and
smooth followed by epidermis, ground tissues and vasculature (Image 3a). The leaf shows a single-layered epidermis with
thin-walled cells. The abaxial epidermal
layer is interrupted by superficial stomata (hypostomatic)
having a cuticular extension and sub-stomatal cavity (Image 3b). Adaxial cells are usually larger than abaxial
ones occupying half the volume of leaf (Image 3a,c). The anticlinal walls of adaxial cells are
undulating (Image 3c). The outer cell
wall is thicker compared to other cell walls which are generally flat to
slightly round. Hypodermis and fibre
bundles are absent in this species. The
mesophyll layer comprises homogenous, thin-walled parenchymatous cells. It is 4–6 cells wide with comparatively
smaller intercellular spaces. Raphide bundles are absent.
Starch grains are the most common cellular inclusion (Image 3c). Vascular bundles are conjoint, collateral and
closed with a larger one in the midrib and smaller in the side vein
region. They are arranged in a single
series across the blade. The vascular
sclerenchyma is absent (Image 3a, d).
Rarity status
As per the present
study and rarity status analysis, the species is considered as very rare as the
rarity index value is 0.8 and the species is located only from the single
locality.
Conservation status
Habenaria rariflora is an endemic
terrestrial orchid of peninsular India.
Based on the current survey and literature study it is revealed that the
species is reported from seven different states of India (Figure 1). In the present study, only a few individuals
were located from Chinchali Village of Dangs District in Gujarat State. The particular site is prone to soil erosion
due to agricultural invasion and grazing.
The ex situ conservation for this species have been made at Wagahi Botanical Garden, Dangs
and Maharaja Sayajirao University of Baroda, Vadodara. The species has not been evaluated for its
threat status till date.
Table 1.
Quantification parameters of rarity (Jalal 2012).
|
Parameters |
Documentation |
Scoring (Quantification) |
1 |
Number of habitats (h¹) |
A number of habitats in which
each orchid species found were recorded. |
Three habitats depending on how
many habitats, a particular orchid occurred in. |
2 |
Number of sites (s¹) |
A number of sites in which each
orchid found were recorded. |
“1” for single site; “2” for < 5 sites; “3” for < 10 sites; “4” for < 15 sites and “5” for > 15 sites. |
3 |
Distribution in India (p¹) |
Divided into six divisions 1. Andaman & Nicobar
Islands 2. Northeastern India 3. Western Himalaya 4. Western Ghats 5. Eastern Ghats 6. Central India |
1 to 4 divisions depending on
the occurrence of species in a particular division. |
4 |
Phytogeographical distribution (p2) |
Indian subcontinent
(Bangladesh, Bhutan, Nepal, Pakistan, Sri Lanka) |
Depending on how many species
are spread in a particular region. |
5 |
Phytogeographical distribution (p3) |
Europe, Sino-Japan, China,
Indo-Malaya, Africa, Australia, and North & South America |
Depending on how many species
are spread in a particular region. |
Identification Key to the Habenaria
of Gujarat
1a. Petals divided
………...……………………………………………………………………………………………………………………………………………………. 2
2a. Plants with inflorescence up
to 45cm tall, leaves spreading all along the stem, flowers greenish white
…........ H. gibsonii
2b. Plants with inflorescence up
to 12–55 cm tall, leaves radical, flowers white ………………………………………………………………..... 3
3a. Leaf solitary or occasionally
two, cordate, appressed to the ground .………………………………………………. H. grandifloriformis
3b. Leaves few,
oblong-lanceolate, not appressed to the ground …………………………………………………………………………. H.
rariflora
1b. Petals undivided
………..………………………………………………………………………………………………………………………………..………….….. 4
4a. Flowers white
…………………………..…………………………………………………………………..………………………………………………………….….. 5
5a. Plants reaching up to 45cm
height, leaves 1–5, radical, spur equal to the length of ovary ……………………….. H.
plantaginea
5b. Plants reaching up to 80–120
cm height, leaves many, cauline, neither spreading nor flat on the ground, spur
much longer
than the length of ovary
……………………………………………………………………………………………………………….…. H. longicorniculata
4b. Flowers green or yellow
………………………………………………………………………………………………………………………………………..……… 6
6a. Leaves radical, clustered at
base of stem, with narrow pale yellow margins, flowers yellow, spur geniculate,
clavate at
apex
…………………………………………………………………………………………………………………………………………..…………….... H. marginata
6b. Leaves clustered about middle of the stem, not
margined, spur linear, incurved ………………………………………….. H. furcifera
For
figure & images - - click here
References
Abraham, A. & P. Vatsala
(1981). Introduction to Orchids with Illustrations and
Descriptions of 150 South Indian Orchids. Tropical Botanic
Garden and Research Institute, Trivandrum, 533pp.
Anonymous (1996). The Biological
Diversity of Gujarat. Gujarat Ecology Commission, Vadodara, 72pp.
Berlyn, G.P., J.P. Miksche & J.E. Sass (1976). Botanical Microtechnique and Cytochemistry. Iowa State
University Press, Iowa, 326pp.
Bole, P.V. & U.M. Pathak (1988). Flora of Saurashtra, Vol. 3. Botanical
Survey of India, Calcutta, 545pp.
Dangat, B.T. (2015). Studies on
Systematics of the Genus Habenaria Willd. (Orchidaceae) in Western
Ghats. PhD Thesis, Shivaji University, Kolhapur,
181pp.
Desai, M.J. (1976). A Contribution to
the Flora of Bansda Forest. PhD Thesis, Sardar
Patel University, Vallabh Vidyanagar, 664pp.
Govaerts, R., P. Bernet, K. Kratochvil, G.
Gerlach, G. Carr, P. Alrich,
A.M. Pridgeon, J. Pfahl,
M.A. Campacci, D.H. Baptista, H. Tigges,
J. Shaw, P.J. Cribb, A. George, K. Kreuz & J.J.
Wood (2020). World Checklist of Orchidaceae. Facilitated by the
Royal Botanic Garden, Kew. Published on the Internet;
http://www.kew.org/wcsp/monocots/ Retrieved 15 April 2020.
Hooker, J.D. (1890). The Flora of British
India, Vol. 6: Orchideae to Cyperaceae. L. Reeve & Co., 792pp.
Jalal, J.S. (2012). Status, threats and
conservation strategies for orchids of Western Himalaya, India. Journal of
Threatened Taxa 4(15): 3401–3409. https://doi.org/10.11609/JoTT.o3062.3401-9
Johansen, D.A. (1940). Plant Microtechnique. New York, London, McGraw-Hill
Book Company, 523pp.
King, G. & R. Pantling
(1898). The Orchids of the Sikkim-Himalaya. Annals of the
Royal Botanic Garden (Calcutta): 1–348.
Misra, S. (2007). Orchids of India: A
Glimpse. Bishen Singh Mahendra Pal Singh, Dehra Dun, 402pp.
Pridgeon, A.M., P.J. Cribb,
F.N. Rasmussen & M.W. Chase (2001). Genera Orchidacearum, Vol. 2, Orchidoideae
(Part 1). Oxford University Press Inc., New York, 464pp.
Raghavan, R.S., B.M. Wadhwa, M.Y. Ansari & R.S.
Rao (1981). A checklist of the plants of the Gujarat. Records
of the Botanical Survey of India 21: 1–127.
Reddy, A.S. (1987). Flora of Dharampur forests. PhD Thesis, Sardar
Patel University, Vallabh Vidyanagar, Gujarat, 686pp.
Ruzin, S.E. (1999). Plant Microtechnique and Microscopy. Oxford University
Press, New York, xi+322pp.
Santapau, H. & Z. Kapadia
(1966). The Orchids of Bombay. Manager of
Publications, Government of India, New Delhi, 239pp.
Shah, G.L. (1978). Flora of Gujarat, Vol. 2. Sardar
Patel University, Vallabh Vidyanagar, 1074pp.
Shah, G.L. (1983). Rare species with a
restricted distribution in South Gujarat, pp. 50–54. In: Jain, S.K. & R.R.
Rao (eds.). An Assessment of Threatened Plant of India. Botanical Survey
of India, Howrah, 334pp.
Singh, S.K., D.K. Agrawala,
J.S. Jalal, S.S. Dash, A.A. Mao & P. Singh (2019). Orchids of India:
A Pictorial Guide. Botanical Survey of India, Kolkata, 547pp.
Suryanarayana, B. (1968). A Contribution to
the flora of Dangs Forest. PhD Thesis, Sardar
Patel University, Vallabh Vidyanagar, Gujarat, 754pp.
Tadvi, D.S. (2014). Floristic
diversity of Dangs, Gujarat. PhD Thesis, The
Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 84pp.
Vora, H.M. (1980). Contribution to
the flora of Dharampur, Kaprada
and Nana Ponda Ranges. PhD Thesis, South
Gujarat University, Surat, Gujarat, 1022pp.
Willdenow, C.L. (1805). Species Plantarum.
Vol. 4. G.C. Nauk, Berlin, 1157pp.