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| Didymocarpus albiflorus Souvann. & Phonepaseuth
in Souvannakhoummane & Phonepaseuth, 2020.
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Abstract
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
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| Fig. 1. Didymocarpus albiflorus Souvann. & Phonepaseuth, A, habit; B. flower top view; C, flower lateral view; D, opened calyx; E, calyx tube; F, opened corolla, showing pistil, stamens and staminodes; G, fertile stamens; H, fruits.
Line drawing by K. Souvannakhoummane from KS-Bio140 (HNL).
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| Fig. 2. Didymocarpus albiflorus Souvann. & Phonepaseuth, A, habit; B, inflorescences and flowers; C, opened corolla, showing pistil, stamens and staminodes; D, fruit.
A & D, photos by P. Phonepaseuth and B–C by K. Souvannakhoummane from KS-Bio140 (HNL).
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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.
