Orchidantha laotica K. Larsen (1961: 349)

Zou, Pu, Xiao, Chun-Fen, Luo, Shi-Xiao, Cui, Chang-Jie, Xu, Kai, Ye, Yu-Shi, Liao, Jing-Ping & Leong-Škorničková, Jana, 2017, Orchidantha yunnanensis (Lowiaceae), a new species from China, and notes on the identity of Orchidantha laotica, Phytotaxa 302 (2), pp. 181-187 : 186

Orchidantha laotica K. Larsen (1961: 349) ( Fig. 3 ).

Type:— LAOS. Wienchan [Vientiane]: Muang Baw [Muang Bo], elev. ca. 200 m, 28 April 1932, A. F. G. Kerr 21284 (holotype K [K-000292162, K-000292163 & K-000292164, a specimen consisting of 3 sheets clearly labeled as sheet 1, sheet 2 and sheet 3], isotype BM-000958173!)

Notes: —The identity of Orchidantha laotica has been unclear since its description which was based on herbarium materials collected by A. F. G. Kerr in evergreen forest in Muang Baw, Wienchan (based on historical maps presumably Vientiane province, Muang Bo). The collection (Leong-Škorničková et al. JLS-1800) presented here in Figure 2 was collected from the same province, near Vang Vieng, about 100 km from the presumed type locality. Our collection also originates from evergreen lowland forest (at elev. ca. 250 m). It agrees very well with the type specimen, the original description and the line drawing (Fig. 4 in Larsen 1961) in terms of shape and size of the plant as well as all floral parts. The only deviation seem to be a colour of the sepals, which is described by Kerr on the label as being greenish-white, while our collection is greenish white at base, but with dense rusty-red tinge. The presence and density of the tinge on sepals might however be variable within population as we have seen on other Orchidantha species.

When Du et al. (1995) reported Orchidantha laotica from Yunnan, they didn’t include any description or illustration. The only specimen cited, Du et al. 950221 ( SWFC) cannot be traced at present. Hence the identity of this record, which was not included in the Flora of China ( Wu & Kress 2000), is still to be verified.

Figures

FIGURE 2. Orchidantha yunnanensis P.Zou, C.F.Xiao & Škorničk. A. Habit; B. Flower (side view); C. Lateral petal (ventral and dorsal view); D. Stamens and style (ventral and dorsal view); E. Ovary (longitudinal section); F. Prophyl G. Second bract; H. Floral bract; I. Lateral sepal (ventral view); J. Lateral sepal (dorsal view); K. Dorsal sepal (dorsal view); L. Labellum; M. stem with pedicel and ovary extension (side view). Scales: B (5 cm); C–E (1 cm); F–M (5 cm).All from P. Zou, C. F. Xiao, C. J. Cui & K. Xu ZP54 (IBSC) and living material of XTBG 20013005. (Drawn by Ms. Yun-Xiao Liu)

FIGURE 3. Orchidantha laotica K.Larsen.A. Habit; B. Ripe open capsule (without seeds); C. Detail of flower with dorsal sepal removed; D. Flower (front view); E. Flower (side view); F. Laterals sepals, dorsal sepal and labellum (scale 1 cm); G. Detail of stigma and stamens enveloped in petals (in side and ventral views) and two petals removed (scale 5 mm); H. Stigma and anthers (petals removed) from ventral, dorsal and side view. All based on Leong-Škorničková et al. JLS-1800. (Photo by J. Leong-Škorničková)