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| Argostemma kamjongense B.S.Sadokpam, S.D.Khomdram & S.D.Yumkham, |
Abstract
A new species, Argostemma kamjongense (Rubiaceae) confined to Kamjong District of Manipur (Northeast India) is described and illustrated. It is akin to closely allied species, A. verticillatum and A. sarmentosum, however can be easily distinguishable by the number of lateral veins on the leaves, size of the leaves, fewer number of bracts, slightly reflexed corolla lobes at maturity, style not exserted and enclosed within anther cone. The taxon’s potential as a good ecological indicator is discussed along with its ecological adaptations for survival. The new species is also provisionally assessed here as Critically Endangered (CR) according to IUCN Red List Categories and Criteria.
Keywords: Argostemma kamjongense, new species, critically endangered, ecological indicator, Manipur (Northeast India)
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| Argostemma kamjongense A–C. Epilithic habit D. Anisophyllous leaves in 2 pairs with single flower in inset E. Habit with single flower showing pubescent stem & bract in inset F. Rudimentary leaves & tubers G. 6–flowered inflorescence H. Calyx I. Corolla, yellowish at base J–K. Agglutinated anthers L. Anther with poricidal dehiscence M. Filiform style with capitate stigma N. 2–locular ovary showing seeds. |
Argostemma kamjongense B.S.Sadokpam, S.D.Khomdram & S.D.Yumkham, sp. nov.
Diagnosis: Argostemma kamjongense differs morphologically from A. verticillatum and A. sarmentosum by having less-er pairs of lateral veins (3–4 pairs versus 4–7 pairs), gen-erally smaller leaves (less than 2.5 cm versus more than 2 cm and up to 10 cm), fewer bracts (1–2 versus in groups of 4 or basally fused in A. verticillatum or more than 2 in A. sarmentosum), corollas yellowish at base (versus greenish at base), corolla lobes slightly reflexed at maturity (versus strongly reflexed at maturity in A. verticillatum and rarely reflexed in A. sarmentosum) and style not exserted and enclosed with anther cone (versus exserted)
Etymology: The specific epithet ‘kamjongense’ refers to the type locality Kamjong District of Manipur State (Northeast India). It was previously a subdivision under Ukhrul dis-trict, and upgraded to the status of district on 8 December 2016.
Bimolkumar S. Sadokpam, Sandhyarani D. Khomdram, Sanatombi D. Yumkham and Dhaneshwor Waikhom. 2023. Argostemma kamjongense (Rubiaceae), A New Species from Manipur, Northeast India. Webbia. 78(2); 79-86. DOI: 10.36253/jopt-14877
