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| Argostemma quarantena Balan & Robi, in Balan, Robi & Sasidharan, 2021. DOI: 10.36253/jopt-9592 |
Abstract
Argostemma quarantena, a new rubiaceous species from Vagamon Hills of southern Western Ghats, India is described and illustrated here. The species shows similarities with two south Indian endemics, A. anupama and A. courtallense, but differs in many qualitative attributes. The present status of genus Argostemma in India is briefly discussed. An artificial key for the identification of Argostemma in Western Ghats is also provided.
Keywords: Argostemmateae, Epilithic, Kottayam, Vagamon Hills
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| Argostemma quarantena sp. nov., (a) Habit. (b) Bract. (c) Flower. (d) Calyx. (e) Split opened corolla. Drawn by Anoop P. Balan. |
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| Argostemma quarantena sp. nov., (d, e) Habitat. (f, g) Habit. (h) Inflorescence. (i) Tuber. (j) Stipule. (k) Calyx with pistil. (l) Corolla and stamens. (m) Seeds. |
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| Argostemma quarantena sp. nov., Habitat. (f, g) Habit. (h) Inflorescence. (i) Tuber. (j) Stipule. (k) Calyx with pistil. (l) Corolla and stamens. (m) Seeds. |
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| (a) Argostemma courtallense. (b) A. rostratum. (c) A. verticillatum. (d, e) Argostemma quarantena sp. nov., Habitat. (f, g) Habit. (h) Inflorescence. (i) Tuber. (j) Stipule. (k) Calyx with pistil. (l) Corolla and stamens. (m) Seeds. |
Argostemma quarantena Balan & Robi, sp. nov.
Diagnosis: The new species is closely similar to A. anupama, but differs in it stem (suberect, terete stem vs erect, quadrangular stem), stipules (1.5–2.0 mm long, deltate stipules vs c. 1 mm long, ovate stipules), leaves (obovate-oblanceolate, densely strigose lamina with 6–10 pairs veins vs ovate-lanceolate, scabrous lamina with 4–6 pairs veins), length and form of umbel (c. 1.5 cm long, congested umbel vs 2.5–3.5 cm long, lax umbel), pedicels (2–3 mm long, stout, hirsute pedicels vs 8–10 mm, slender, pubescent pedicels), calyx lobes ( 2.5 mm long vs 4.0 mm long), corolla lobes (4.5 mm long, triangular vs 5.5–6.0 mm long, lanceolate) and anther filaments (not twisted vs twisted). It also shows similarities with A. courtallense, but differs mainly by its stipules (1.5–2.0 mm long, deltate stipules vs 7–8 mm long, ovate stipules), shape and indumentum of leaves (anisophyllous leaves with obovate-oblanceolate and densely strigose lamina vs isophyllous leaves with ovate-orbicular and sparsely pubescent lamina), number of lateral veins (6–10 pairs vs 4–7 pairs lateral veins), umbel (c. 2 cm long, congested umbel vs 4–8 cm long, lax umbel), corolla lobes (4–4.5 mm long vs 7–8 mm long) and anthers (ca 1.5 mm long, white anthers vs ca 3 mm long, yellow anthers). (Table 1).
Etymology: The specific epithet quarantena indicates the out-break of COVID-19 corona virus across the world in 2020. The term quarantena was used in 14th–15th century Venetian language for a forty-day isolation period. The new species was described during the 2020 quarantine period imposed to curb the spread of the COVID-19 virus. This species is a dedication to the lakhs of people including eminent botanists and scientists who have lost their lives due to the COVID-19 virus in the year 2020.
Distribution and ecology: Argostemma quarantena is known only from its type locality at Vagamon Hills, South India. Vagamon hills are traversed by numerous perennial fast flowing streams which originated from evergreen forest patches and pseudosholas at 1000–1400 m elevations asl. This species is thriving on boulders beside such streams and shaded areas, growing with mosses and ferns.
Anoop Puthuparampil Balan, Aloor Jose Robi and Nanu Sasidharan. 2021. Argostemma quarantena (Rubiaceae, Ruboideae), A New Species from southern Western Ghats, India. Webbia: Journal of Plant Taxonomy and Geography. 76(1); 47-52. DOI: 10.36253/jopt-9592
