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| Cyphostemma calcarium Rabarij & L.M.Lu, in Rabarijaona, Rafaralahy, ... et Lu, 2021. (Illustration by Ai-Li Li). |
Abstract
Cyphostemma calcarium Rabarij & L.M.Lu, sp. nov., is herein described as a new species found on limestone outcrops in northern Madagascar. Its diagnostic morphological characteristics were compared to the species occurring in the Ankarana Special Reserve. We present detailed descriptions, illustrations, distribution map, and a preliminary conservation assessment of the species. An identification key to all known species of Cyphostemma from the Ankarana Special Reserve is also provided.
Keywords: Ankarana, Cyphostemma, Cyphostemma calcarium, Madagascar, Vitaceae
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| Cyphostemma calcarium sp. nov. A branches showing puberulent leaves and infructescence B–E seed morphology from Rakotovao C. et al. 6376 (Dorsal, ventral, lateral, and cross-section presented from left to right) Photo by Rakotovao Charles, Missouri Botanical Garden. Scale bars: 1 mm |
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| Cyphostemma calcarium sp. nov. A branches showing the inflorescence and infructescence and the bark with distinct lenticels B trichomes on the abaxial leaflet surface C flower bud constricted at the middle D flower with petals and stamens removed to show the floral disc of 4-large free glands E fruit with a persistent stigma (Illustration by Ai-Li Li; based on Rakotovao C. et al. 6376, TAN). |
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| Comparison of two shrubby Cyphostemma species with 3-foliolate leaves in the Ankarana Special Reserve A–E Cyphostemma calcarium sp. nov. A branches showing puberulent leaves and infructescence B–E seed morphology from Rakotovao C. et al. 6376 (Dorsal, ventral, lateral, and cross-section presented from left to right) F–J Cyphostemma rutilans Desc. F branches with glabrous leaves and inflorescence G–J seed morphology from Bardot-Vaucoulon M. 817 (Dorsal, ventral, lateral, and cross-section presented from left to right). Photos by Rakotovao Charles, Missouri Botanical Garden (A); Billiet Frieda, Meise Botanic Garden (F). The red arrow indicates an extra layer of endotestal sclereids covering the ventral infolds. Scale bars: 1 mm |
Cyphostemma calcarium Rabarij & L.M.Lu,
Diagnosis: Cyphostemma calcarium is most closely comparable to C. rutilans Desc. in morphology. It differs from the latter in having distinct pubescent branches (vs. branches entirely glabrous in C. rutilans); leaves minutely puberulous and shiny on the adaxial surface, abaxial surface densely whitish pubescent to velvety particularly on the veins (vs. leaves entirely glabrous and shiny on both sides in C. rutilans); and leaflets broadly oblong or elliptic, base cuneate (vs. leaflets narrowly ovate, base subcordate in C. rutilans). Seeds of C. calcarium are ellipsoid in outline, 7–7.5 × 3–3.5 mm, surface rugose to ± muricate (vs. seeds globose, 5–6.5 mm in diameter, surface strongly rugose in C. rutilans).
Etymology: The epithet of the species refers to the habitats on limestone outcrops.
Distribution and habitat: It grows on limestone outcrops in northern Madagascar at an altitude of 90–300 m.
Romer Narindra Rabarijaona, Valisoa Louisicaël Rafaralahy, Charles Rakotovao, Rindra Manasoa Ranaivoson, Bing Liu, Zhi-Duan Chen, Jun Wen and Li-Min Lu. 2021. Cyphostemma calcarium, A New Species of Vitaceae from the Ankarana Special Reserve, Madagascar. PhytoKeys. 180: 73-80. DOI: 10.3897/phytokeys.180.69194
