Peliosanthes micrantha Averyanov & Tanaka (2013: 5)

Averyanov, Leonid V., Nguyen, Van Canh, Tanaka, Noriyuki, Nguyen, Khang Sinh & Maisak, Tatiana V., 2023, Three new taxa and two noteworthy species of Peliosanthes (Asparagaceae, Convallarioideae) from Laos and Vietnam, Phytotaxa 609 (3), pp. 209-221 : 215

Peliosanthes micrantha Averyanov & Tanaka (2013: 5) ( Fig. 3 )

Type:— VIETNAM. Southern Vietnam , exported originally from southern Vietnam to Main Botanical Garden (Moscow), pressed from plants cultivated at Komarov Botanical Institute Garden grown from immature specimen imported from southern Vietnam by unknown collector without exact locality and collecting number, collected from cultivated specimen on 24 April 2012 by L. Averyanov . Holotype LE: LE01049429 (http://re.herbariumle.ru/01049429). Photos of the cultivated plant used for preparing the holotype — LE: LE01122702 (http://re.herbariumle.ru/01122702). Epitypes : LE: LE01049025 (http://re.herbariumle.ru/01049025) & LE01049065 (http://re.herbariumle.ru/01049065).

Specimens examined:— LAOS. Precise locality unknown, 2017, Averyanov L . et al., s.n., herbarium specimen prepared from cultivated plant on 13 April 2023 by L . Averyanov AL2212 , LE: LE01170558 (http://re.herbariumle.ru/01170558). Photographs of the cultivated plant used for preparing the voucher herbarium specimen: LE: LE01124108 (http:// re.herbariumle.ru/01124108) . VIETNAM. Thua Thien Hue Province: Nam Dong District, Thuong Quang Commune , 19 January 2019, H. L . Tuan Anh et al., LTA 920 LE: LE01050259 (http://re.herbariumle.ru/01050259). Dak Lak Province: wild collected plant cultivated in V. C . Nguyen’s private garden, 22 October 2017, V. C . Nguyen , L . Averyanov , T . Maisak , AL 389 LE: LE01049907 (http://re.herbariumle.ru/01049907). Dak Lak Province: wild collected plant cultivated in V. C . Nguyen’s private garden, 22 October 2017, V. C . Nguyen , L . Averyanov , T . Maisak s.n., specimen prepared from cultivated plant, 1 April 2021, L . Averyanov AL 389 garden number 17547 LE: LE01077032 (http:// re.herbariumle.ru/01077032). Dak Nong Province: Krong No District, Nam Nung Commune, Nam Nung Natural Conservation Area , 600–800 m, 26 April 2017, H. P . Nguyen, AL 397 (Herbarium of the National Institute of Medicinal Materials , NIMM) . Specimen prepared from cultivated plant, 1 April 2021, L . Averyanov AL 397 garden number 17546 LE: LE01077031 (http://re.herbariumle.ru/01077031) .

Distribution: — Laos (sine loco, new record) and Vietnam (Thua Thien Hue, Dak Lak, and Dak Nong Provinces).

Notes: —Here we report Peliosanthes micrantha , so far known from central (Thua Thien Hue Province) and southern (Dak Lak and Dak Nong Provinces) Vietnam, as a new addition to the flora of Laos. This species is distinct with such traits as small spherical flowers, prominently verruculose perianth, a sub-spherically incurved corona wall thinning toward both the base and the apex, a bottle-shaped, nearly superior pistil, and ovules not more than two in each locule. Compared with plants from Vietnam, the plant from Laos had broadly (somewhat triangular) ovoid (vs. spherical) floral buds and flowers, and triangular ovate (vs. oblong-elliptic), distally acute (vs. obtuse) outer perianth segments.

It is noteworthy that the flowers of P. micrantha tend to scarcely or only narrowly open, and most of them drop without setting fruits (seeds) at least under cultivation, implying that their pollination is achieved only by very specific pollinators.

Interestingly, P. inaperta Aver. & N.Tanaka in Averyanov et al. (2016: 209) described from Khammouane Province in central Laos also exhibits a similar mode of flowering, though its flowers remain more tightly closed during anthesis. Peliosanthes micrantha and P. inaperta differ in many respects. For example, compared with P. inaperta , P. micrantha has more ovoid-ellipsoid (vs. spherical) flowers, less thickened, laterally less strongly involute perianth segments (especially inner segments), and a nearly superior (vs. typical half-inferior) pistil. The perianths of both species are, however, similar in being prominently incurved and verruculose, though the latter character state is less distinct in P. inaperta .

Figures

FIGURE 3. Peliosanthes micrantha. A. Habit of flowering plant, viewed from above. B. Basal portion of flowering plant.C. Leaf margins, adaxial (left) and abaxial side (right). D. Flowering plant. E. Inflorescences. F. Close up of inflorescence. G. Portion of inflorescence with some open flowers. H. Rachis with floral bracts, front flowers removed. I. Detached cataphylls, leaves, inflorescences at various stages, and seed-bearing withered flower. J & K. Closed or slightly open flowers. L. Flowers with pedicel, rear view. M. Two outer (above) and two inner (below) perianth segments (abaxial sides). N. Outer perianth segment, abaxial surface. O. Coronas, views from above and side. P. Mature flowers with dehisced anthers, longitudinally sectioned. Q. Basal portion of flower cross-sectioned except pistil (left), and corona and ovary cross-sectioned (right). R. Coronas viewed from above and below. S. Young green seeds of a withered flower. Photos, photo correction, and plate design by L. Averyanov and T. Maisak, specimen L. Averyanov AL2212.