Eulophia obtusa

Eulophia obtusa, a showy and distinctive species of orchid, popularly known as the ground orchid, recorded from Bangladesh, North India and Nepal (Sourav, M.S.H, et al. 2017). This orchid growing in seasonally in grassland. It is a grass associated orchid species. A Bangladesh based renowned botanist and ornithologist Md Sharif Hossain Sourav first described this rare species from Bangladesh in 2017 (Sourav, M.S.H, et al. 2017). There are only three collections in the Kew Herbarium dates from 1902, which suggests that it is quite a rare species. It is as critically endangered (CR) in Bangladesh according to the IUCN Red Listing criteria. Very recently this species rediscovered from India after 118 years.

Eulophia obtusa
A plant at its habitat with bloomed flower from Bangladesh
Scientific classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Orchidaceae
Subfamily: Epidendroideae
Genus: Eulophia
Species:
E. obtusa
Binomial name
Eulophia obtusa
Synonyms

Description: Terrestrial, seasonally deciduous herb, bearing underground corms. Corm white, dome-shaped, 2.5 – 3.1 cm wide and 3.3 – 5.5 cm high, lying 10 – 20 cm below ground, bearing vermiform, white roots. Shoots 1 – 5-leaved, usually bifoliate, basal part formed by sheaths enveloping the base of the inflorescence as well as the leaf-bases. Leaves appearing with the inflorescence, grass-like, 35 – 50 cm long, 0.15 – 0.5 cm wide, linear, slightly plicate, apex acuminate, midrib prominent, sheathing at base. Inflorescence erect, 40 – 60 cm tall; peduncle terete with a few distant, c. 5 cm long, linear-triangular, sterile bracts; rachis up to c. 10 cm long, bearing 4 – 12 flowers usually opening simultaneously and more or less evenly spaced. Flower 3 – 4 cm diam.; sepals and petals white, lip white tinged pink, with numerous deeper purplish pink, branching veins, zone surrounding the mouth of the spur light green; calli white, green in the basal part of the lip; spur green; column creamy white, apex red-purple, anther yellowish tinged green, with faint purple markings. Floral bracts c. 1.4 cm long, lanceolate, acuminate, much shorter than the combined length of pedicel and ovary. Pedicel with ovary c. 24 mm long, curved, glabrous, terete, ovary ribbed. Dorsal sepal c. 2.0 × 0.5 cm, oblong-lanceolate, acute, 7-nerved; lateral sepals similar, c. 1.8 × 0.5 cm. Petals 1.8 × 0.6 cm, oblong-lanceolate, obtuse. Lip 2.1 × 1.7 cm when flattened, at right angles to the column, 3-lobed; lateral lobes basal, erect, c. 5 × 4 mm, semi-elliptic, rounded; midlobe c. 1.7 × 1.3 cm, elliptic, almost truncate, margins undulate; callus complex, consisting of 3 – 4 short, transverse ribs on either side of the mouth of the spur, and 5 longitudinal ribs of unequal size and height occupying most of the median part of the midlobe; veins thickened; spur c. 6.7 mm long, conico-cylindrical, obtuse, curved forward and appressed on the abaxial surface of the labellum. Column 8 mm long, with short foot. Fruit not seen (Sourav, M.S.H, et al. 2017).

The only known site of Eulophia obtusa in Bangladesh is situated in the high Barind tract, one of the major agro-ecological regions comprising about 79% of Godagari upazila. The area lies at about 15 m above sea level, and is not normally flooded, although the grassland in which the orchid occurred was usually water-logged during the peak of the rainy season. The vegetation is composed of grasses like Imperata cylindrica and Saccharum spontaneum as well as herbs and shrubs, including Amorphophallus margaritifer, A. paeoniifolius, Boerhavia diffusa, Chrozophora rottleri, Colocasia esculenta, Commelina benghalensis, Croton bonplandianus, Cyanotis cristata, Cyperus sp., Digera muricata, Euphorbia hirta, Ficus hispida, Kyllinga microcephala, Leucas lavandulifolia, Lippia alba, Parthenium hysterophorus, Phyllanthus virgatus, Solanum villosum, Uraria picta, and others. In North India, Eulophia obtusa has been found in freshwater swamps (Deva & Naithani 1986). The elevations have not been recorded for the collections we have seen, but they are probably all from below 200 m asl.

Flowering: June – July; fruiting: not seen, but local informants stated that they had seen the plants in fruit (Sourav, M.S.H, et al. 2017).

References

    Sourav, M.S.H, Halder, R., Kumar, P. et al. Kew Bull (2017). Eulophia obtusa (Orchidaceae: Epidendroideae: Cymbideae) an addition to the flora of Bangladesh, with notes on its ecology and conservation status: Kew Bull 72: 19.https://doi.org/10.1007/s12225-017-9689-2

    Deva, S. & Naithani, H. B. (1986). The Orchid Flora of North-west Himalaya. Print and Media Associates, New Delhi.

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