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| Begonia kalimantana Randi & Ardi, in Randi, Mustaqim, Kadhafi, Nursub’i et Ardi, 2025. |
Abstract
Two new species of Begonia were discovered during an expedition to Mount Bukit Raya, the highest peak in Kalimantan, Indonesian Borneo. Full descriptions with colour plates and distribution map are provided.
Begonia bukitrayaensis, Begonia kalimantana, herbs, national park,plant taxonomy, west Malesia, Eudicots
Begonia bukitrayaensis Randi & Mustaqim, sp. nov.
§. Petermannia
Diagnosis:—Begonia bukitrayaensis is similar to Begonia chakensis S.Julia & C.Y.Ling (2015: 108) in its creeping habit and ovate,
asymmetric leaves, but differs in having glabrous vegetative parts except for stiff red bristle-like trichomes between the veins on
the adaxial leaf surface (vs. densely pilose stems, petioles, and abaxial veins in B. chakensis). The leaves of B. bukitrayaensis have
red-dentate margins and a rounded to slightly cordate base (vs. minutely serrate margins and an acute or slightly cordate base). The
stipules are falcate with recurved margins and a cuspidate apex (vs. broadly ovate, serrate, and acute). Male flowers bear fewer
stamens (25–28 vs. 39–40).
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| Begonia kalimantana Randi & Ardi. A. Plant habit in the wild; B–C. Adaxial and abaxial surface of leaves; D. Stipule; E. Stem and inflorescences; F. Staminate flower (top view); G–H. Pistillate flower (top and side view). Photographs: A. Randi (all from Randi AR-1366). |
Begonia kalimantana Randi & Ardi, sp. nov.
§. iPetermannia
Diagnosis:—Begonia kalimantana resembles Begonia eutricha Sands (1997: 434) in erect habit with distichous and falcate leaves,
however it can be easily distinguished by striking consistent color pattern, dark olive green with shiny silvery white stripe along the
midrib (vs. plain green), lamina surface hirtellous (vs. densely hispid); shorter male flower pedicels 8–12 mm long (vs. 22–24 mm
long); ovary reddish and glabrous (vs. ovary white tinged with pink, and covered with soft white erect hairs), wings margin glabrous
(vs. ciliate), and longer ovary beaked 3–5 mm long (vs. 1 mm long).
Agusti RANDI, Wendy A. MUSTAQIM, Andi M. KADHAFI, Firasadi NURSUB’I and Wisnu H. ARDI. 2025. Two New Species of Begonia (Begoniaceae) from Bukit Baka Bukit Raya National Park, Kalimantan, Indonesia. Phytotaxa. 704(2); 99-105. DOI: doi.org/10.11646/phytotaxa.704.2.1 [2025-06-06]
