Aspidistra nikitensis Kalyuzhny & Vislobokov, 2022

Kalyuzhny, Sergey S., Vislobokov, Nikolay A., Luu, Hong Truong, Plugatar, Yury V., Kuznetsov, Andrey N., Kuznetsova, Svetlana P., Korzhenevsky, Vladislav V. & Vin’Kovskaya, Oksana P., 2022, Aspidistra nikitensis (Asparagaceae, Nolinoideae), a new species from Vietnam, Phytotaxa 574 (4), pp. 289-294 : 290-292

Aspidistra nikitensis Kalyuzhny & Vislobokov sp. nov. ( Fig. 1 ).

Diagnosis: Aspidistra nikitensis is morphologically similar to A. hainanensis species complex but differs in convex stigma with projections.

Type:— Vietnam, Gia Lai province, K’Bang district, Kon Chu Rang Nature Reserve , primary evergreen broad-leaved forest, around point 14º30’09.0’’ N, 108º34’10.7’’ E, elevation 1040 m a.s.l., not common, 1 March 2021, S. Kalyuzhny Ktg 25-21/194-21, the herbarium specimen prepared from the living cultivated plant by S. Kalyuzhny (holotype YALT) (including conserved flower) .

Plant perennial, evergreen, herbaceous, rhizomatous, glabrous. Rhizome terete, epigeous to hypogeous, creeping to ascending, branching, 2.5–3.4 cm in diam., densely nodal. Roots grey or greenish, 2–3.3 mm in diam., with dense hairs persistent up to root base. Rhizomes with regularly repeating units, each comprising distichously arranged phylloms: a few cataphylls followed by 3–5 foliage leaves. Cataphylls dull reddish-brown, oblong, 15.5–19.2 cm long, 1.8–2.5 cm wide. Leaves not divided into petiole and lamina. Leaf dark to light green, linear, distally narrowly acuminate, gradually narrowing towards base, 78–105 cm long, 2.1–3.2 cm wide, with finely serrate margin, with prominent midvein on lower surface and 2–3 inconspicuous secondary veins at both sides. Leaf base stiff, erect, adaxially sulcate, 3.7–4.5 mm wide. Peduncle (specialized reproductive shoot) pale green with purple spots, 2.3–4.8 cm long, 1.9–3.1 mm in diam., curved at top so that perigone mouth directed horizontally to the surface, with 3–5 distichously arranged widely ovate acuminate scale purple spotted leaves 8.2–12 mm long, 4–7.2 mm wide. Flowers odorless, solitary at top of peduncle, located at soil level. Perigone completely darkish-burgundy, campanulate, 3.1–3.9 cm long, 2.4–3.6 cm in diam.; tube 12–20 mm long, 7.2–13 mm in diam.; lobes 6, triangular-ovate, slightly acuminate, 11–19 mm long, 3.7–7.2 mm wide, basally with 2 prominent longitudinal keels. Stamens 6, in the same number as perigone lobes, inserted at base of perigone tube, at radii of tepals; filaments basally purple, apically white, cylindrical, short, ca. 1 mm long; anthers subsessile, 2.8–3 mm long, 2.1–2.7 mm wide, introrse. Pistil mushroom-shaped, 7–9 mm long. Style white, cylindrical, 4.4–5 mm long, 3.7–4.2 mm in diam. Stigma darkish-burgundy above, white with purple spots along margin below, shallowly trilobate, up to 1.2 cm in diam., the upper surface convex with projections covered with sharp needle-like outgrowths, shallowly 3-lobed. Ovary inconspicuous, superior, 3-locular. Fruits unknown.

Additional studied specimens:— Plants cultivated in The Nikitsky Botanical Gardens RAS (accession number: Ktg 25-21/194-21) and in Botanical Garden of Irkutsk State University (accession numbers: Ktg 8-21/174-21; Ktg13- 21/180-21), Russia .

Etymology:—A new species of Aspidistra was named after one of the oldest botanical gardens in Russia (the Nikitsky Botanical Gardens – National Scientific Center of the Russian Academy of Sciences) where the plants of the new species are cultivated.

Distribution and Ecology:—The new species is currently known only from Gia Lai province in Vietnam, where a single flowering specimen was verified as a representative of the new species. However, Aspidistra plants similar to the new species (by vegetative features) were rather frequent in several areas of Kon Chu Rang Nature Reserve. For this reason, we assume that A. nikitensis can be treated as locally common. Aspidistra nikitensis occurs on mountain slopes under the canopy of dense tropical mountain polydominant forest of middle elevation. The upper storey (24–26 m high) includes Ormosia balansae Drake (Fabaceae) , Dipterocarpus alatus Roxb. and Shorea sp. (Dipterocarpaceae) , Castanopsis sp. (Fagaceae) , Diospyros buxifolia (Blume) Hiern (Ebenaceae) , and also comprises hemiepiphytic Ficus spp. (Moraceae) , Smilax aspericaulis Wall. ex A.DC. , S. corbularia Kunth (Smilacaceae) . In the canopy we marked Calamus rudentum Lour. , Caryota mitis Lour. , Molineria capitulata (Lour.) Herb. , Dianella ensifolia (L.) Redouté.

Phenology:— Aspidistra nikitensis was observed blooming in mid-April in natural habitat.

Taxonomic relationships:— Aspidistra nikitensis possesses linear leaves and trimerous flowers with a mushroomshaped pistil. By these features, the new species resembles and closely relates to the A. hainanensis Chun & How (1977: 533) species complex sensu Tillich & Averyanov (2012), including species as A. linearifolia Wan & Huang (1987: 220) , A. oviflora Averyanov & Tillich (2015: 371) , A. triradiata Vislobokov (2015: 269) , A. viridiflora Vislobokov & Nuraliev in Vislobokov et al. (2017: 203) and A. yingjiangensis Peng (1989: 173) . However, the upper surface of a stigma of A. nikitensis is convex with relatively large projections. Thus, the new species shows a unique structure of stigma within this complex of related species and can be clearly distinguished among them. In stigma structure, A. nikitensis resembles A. longanensis Wan (1985: 151) but differs in shape of leaves (linear leaves not divided into petiole and lamina vs. leaves with petiole 9–17.5 cm long and oblong-elliptic lamina) and perigone merism (6-lobed vs. 8-lobed perigone).

Conservation status:—Only one blooming specimen of the species was found in the type locality. However, as exploration of the area has been very fragmentary, we have little information on the actual occurrence of this species, which could be more widely distributed in the intermountain valleys of the province. Also, we have no information on any current threats to the habitat of the species. We here propose a status of ‘Data Deficient’ (DD) for this species according to IUCN categories and criteria ( IUCN 2019).

Figures

FIGURE 1. Aspidistra nikitensis. A. Flower, front view. B. Flower with partly removed perigone, side view. C, D. Longitudinal sections of flower. E. Plant with flowers. F, G. Habit.