|Didymocarpus albiflorus Souvann. & Phonepaseuth|
in Souvannakhoummane & Phonepaseuth, 2020.
Didymocarpus albiflorus, a new species from central Lao PDR, is described and illustrated with photographs. The new species is similar to D. middletonii and D. brevipedunculatus, but can be distinguished by a combination of characters (see diagnosis and note). A detailed description, illustration, photographs, distribution, ecology and provisional conservation assessment and key to the species of Didymocarpus in the flora of Lao PDR are provided.
Keyword: Chayamaritia, Didymocarpus middletonii, Didymocarpoideae, Gesneriaceae, Plant taxonomy, Flora of Lao PDR
Didymocarpus albiflorus Souvann. & Phonepaseuth, sp. nov.,
Diagnosis. The new species is similar to Didymocarpus middletonii, but differs in having longer stem, calyx tube funnelform, pale green with reddish blotches, glabrous, corolla white with 9 grayish stripes inside.
Distribution. Currently known from type locality at Darn Sinxay temple area, about 20 km from central Vientiane.
Ecology and habitat. The species grows on shaded rocks covered with moss in mixed deciduous forest with sufficient seasonal run-off water, at an elevation of 210 m a.s.l. It grows with Begonia martabanica A.DC. (Begoniaceae) and Monolophus bracteatus (K.Larsen & S.S.Larsen) Veldk. & Mood (Zingiberaceae). The massive flowering and fruiting were observed in August and September.
Vernacular name. ດອກແກຢົກຂາວ ‘Dok Kea Yok Khao’ [funnel white jade flower] (suggested here).
Etymology. The specific epithet is derived from the white flowers.
Notes. The new species is similar to Didymocarpus middletonii, but differs in having longer stem (ca. 17 cm long versus 0.3–0.7 cm long), calyx tube funnelform, pale green with reddish blotches, glabrous (vs. tube urceolate, dark red, multicellular eglandular hairs), corolla white with 9 grayish stripes inside (vs. light red at base, reddish to blackish purple with 9 dark stripes inside). This species is also similar to D. brevipedunculatus Y.H.Tan & Bin Yang, but differs in that the leaves ovate-elliptic (vs. ovate), inflorescences occur on axil near the top of stem with 3–4 flowers (vs. one per axil with numerous flowers), peduncles ascending to erect (vs. pendulous), calyx pale green with reddish blotches (vs. pale green to white), corolla inside with 9 white-grayish longitudinal (vs. inside with 9 purplish to deep red longitudinal stripes), ovary multicellular eglandular hairs (vs. glabrous).
Keooudone Souvannakhoummane and Phongphayboun Phonepaseuth. 2020. Didymocarpus albiflorus (Gesneriaceae), A New Species from Vientiane Capital, Lao PDR. Taiwania. 65(2); 109-113.