Aspidistra congestiflora Aver., Vislobokov & Nuraliev, 2025

Averyanov, Leonid V., Vislobokov, Nikolay A., Nuraliev, Maxim S., Maisak, Tatiana V., Krupkina, Ludmila I. & Doan, Nga Thi, 2025, Aspidistra congestiflora (Asparagaceae, Convallarioideae), a new species from central Laos, Phytotaxa 710 (2), pp. 184-190 : 185-188

Aspidistra congestiflora Aver., Vislobokov & Nuraliev , sp. nov. ( Fig. 1 )

Diagnosis: — Aspidistra congestiflora is morphologically most similar to A. zhangii , differing in longer petioles (16–44 cm vs. 4–12 cm long) and color of perianth tube and pistil (purple-violet vs. white).

Type: — LAOS. Originally collected in Vientiane Province: Vang Vieng District, Oa Hom Village , around point 19°05’57.0’’N 102°23’19.9’’E, secondary broad-leaved evergreen and semideciduous dry forest on very steep rocky mountain slopes composed by solid marble-like highly eroded limestone at elevation of 650–750 m a.s.l., terrestrial clustering herb with very short rhizomes on shady slope, not rare, 22 March 2017, L. Averyanov, N. T. Hiep, N. S. Khang, C. Q. Ngan, T. Maisak, Khamla Inkhavilay, Hongthong Southyvohanh, Pinmany Sisavath, Chanthala Cheuaysamphanh. Herbarium specimens and photos prepared from cultivated plant on 28 March 2025 by L. Averyanov, T. Maisak, LA-VN 1554/5 (holotype LE LE01282398 https://en.herbariumle.ru/?t=occ&id=258876, isotype LE01282399 https://en.herbariumle.ru/?t=occ&id=258877; photos of the plant used for the preparation of the type specimens: LE LE01255683 https://en.herbariumle.ru/?t=occ&id=258635, LE01255684 https://en.herbariumle.ru/?t=occ&id=258636) .

Etymology: —The species name refers to its numerous flowers densely crowded on short branched rhizome. Moreover, the entire plant in its living state is highly reminiscent of Peliosanthes Andrews (1810 : t. 605) due to its commonly abundantly branched rhizome with very short branches, that leads to a caespitose or clustering plant appearance.

Description:—Plant terrestrial, herbaceous, perennial, evergreen, rhizomatous, glabrous (except for having root hairs). Rhizome epigeous, horizontal to ascending, terete, short, abundantly and densely branched; individual branches less than 3 cm long, (8)9–10(11) mm in diameter, with very short internodes, covered by numerous bracts (cataphylls). Rhizome with regularly repeating units, each unit comprising 3–4(5) cataphylls followed by a single foliage leaf; rhizome branches consisting of 1–3(4) units, sometimes having appearance of a group of closely spaced leaves. Roots several per rhizome branch, dull grey, (4.5)5(5.5) mm in diameter. Cataphylls erect, convolute and appearing tubular, oblong to ensiform (when flattened), coriaceous, pale to dark brown, (2)4–12(15) cm long, (6)7–12(14) mm wide, persistent. Leaves to 70 cm long, distinctly petiolate. Petiole rigid, erect, straight, grassy green, (16)20–40(44) cm long, 4.5–5.5 mm in diameter, at base slightly thickened to 7 mm in diameter, sulcate adaxially. Leaf blade upright or almost horizontal, arcuate, narrowly elliptic to elliptic, broadly cuneate at base, acute to shortly acuminate at apex, uniformly glossy green, (16)20–30(35) cm long, (4.5)5–7.5(8.5) cm wide, parallel-veined, with median and secondary veins distinct on both sides. Inflorescences axillary, numerous, providing the rhizome with appearance of bearing densely crowded flowers. Peduncle erect to suberect, white and sometimes with pink tint, (4)5–9(11) mm long, 2.5–3 mm in diameter, bearing (2)3(4) more or less distant sterile bracts. Bracts cymbiform, obtuse to acute, rather scarious, broadly ovate to broadly ovate triangular (when flattened), dark violet, (6.5)7–11(12) mm long and wide, smooth or finely verruculose outside. Flowers solitary at top of peduncle. Perianth dark violet to almost black on both sides, gradually becoming light purple to almost white towards base, (1.2)1.4–1.5(1.6) cm long, (13)14–17(18) wide, halfway dissected into lobes; tube obconoid (funnel-shaped); lobes 6, apparently in two whorls due to slightly overlapping bases, erect to slightly spreading, subequal, triangular, obtuse at apex, (6)6.5–8(8.2) mm long, (8.6)9–10(10.4) mm wide at base, smooth or finely verruculose on both sides, with entire margin. Stamens 6, inserted at middle of perianth tube in the same radii with tepals; anthers sessile to subsessile, ellipsoid, bright rich yellow, (2.8)3–3.2(3.4) mm long, 1.6–1.8 mm wide, introrse. Pistil widely obconoid, white at base, purple-violet in apical half, (7.5)8–9(9.5) mm long, 10–12 mm wide at apex; style with 6 very prominent longitudinal ridges alternating with stamens and 6 less prominent longitudinal ridges opposite stamens; ridges finely irregularly denticulate. Ovary superior, small, externally not delimited from style. Stigma obscurely hexagonal, convex, purple-violet to dull violet, 10–12 mm across, finely papillulate, with 6 rather obscure roundish lobes and indistinct irregular radial fissures. Fruits unknown.

Ecology and phenology: —Evergreen and semideciduous dry forests on karstic, marble-like limestone at elevations of 650–750 m a.s.l., commonly on very steep rocky mountain slopes. Flowers in March–April (under cultivation).

Distribution: — Laos: Vientiane Province (Vang Vieng District). Endemic to a karstic limestone area near Vang Vieng Town.

Conservation status: — Aspidistra congestiflora is currently known from a single location, where it was observed to be rather common, scattered on very steep and often inaccessible slopes. Before comprehensive field studies, the conservation status of the species may be assessed as Data Deficient (DD), or provisionally as Least Concern (LC). At the same time, the very narrow known distribution of the species will probably lead to the need of its protection in the near future.

Taxonomic relationships: — Aspidistra congestiflora differs from most of its congeners in the following combination of morphological traits: obconoid perianth tube, triangular perianth lobes without appendages, and widely obconoid pistil with prominent longitudinal ridges. The new species is most similar to A. zhangii Aver., Tillich & K.S.Nguyen in Averyanov et al. (2016: 62), which is characterized by the same set of structural traits. Aspidistra congestiflora differs from A. zhangii in petioles 16–44 cm (vs. 4–12 cm) long and almost entirely purple-violet flower (vs. flower with white perianth tube and pistil).

Nine more species of Aspidistra (endemic to China or Vietnam) are known to have campanulate, urceolate or obconoid perianth tube, triangular (as opposed to linear) perianth lobes without appendages, and widely obconoid pistil (with its height/diameter ratio not exceeding 1.5) with prominent longitudinal ridges. We consider additional types of perianth tube in this comparison, because their delimitation is not always straightforward, and intermediate cases occur. Aspidistra congestiflora differs from these species mainly as follows:

from A. cadamensis Ly & Tillich (2017: 84) in 6 prominent and 6 less prominent (vs. 12 subequally prominent) longitudinal ridges on the style, and purple-violet convex (vs. white concave) stigma;

from A. chishuiensis S.Z.He & W.F.Xu in Xu et al. (2010: 118) in purple-violet (vs. white) pistil and convex (vs. concave) stigma;

from A. leipingensis Z.B.Ding & R.K.Li in Ding et al. (2024: 116) in flowers with 6 (vs. 8) tepals and stamens, 12-ridged (vs. 8-ridged) style and purple-violet convex (vs. pale yellow hemispherical) stigma;

from A. lianhuatanensis H.C.Xi, R.K.Li & W.G.Wang in Xi et al. (2025: 331) in peduncle 4–11 mm (vs. 15–45 mm) long, erect to slightly spreading (vs. reflexed to revolute) perianth lobes, and purple-violet (vs. white) stigma;

from A. mirostigma Tillich & Škorničk. in Leong-Škorničková et al. (2014: 34) in obconoid (vs. urceolate) perianth tube and purple-violet (vs. adaxially yellowish green) perianth lobes;

from A. nitens Aver., K.S.Nguyen & Tillich in Averyanov et al. (2021: 27) in flowers with 6 (vs. 8–10) tepals and stamens and obconoid (vs. urceolate) perianth tube;

from A. shimentaiensis C.X.Peng, Y.Q.Li & C.R.Lin in Peng et al. (2023: 88) in dark violet perianth (vs. perianth yellow with purple-red stripes), style with 6 prominent and 6 less prominent (vs. 12 subequally prominent) longitudinal ridges and purple-violet stigma (vs. stigma white with purplish red margin);

from A. shiwandashanensis C.R.Lin & W.B.Xu in Lin et al. (2023: 122) in flowers with 6 (vs. 8) tepals and stamens and 12-ridged (vs. 4-ridged, i.e. quadrangular in cross section) style;

from A. yizhouensis P.Pan & C.R.Lin in Pan et al. (2016: 85) in petioles 16–44 cm (vs. 6–12 cm) long, obconoid (vs. urceolate) perianth tube, purple-violet (vs. adaxially yellow) perianth lobes, and purple-violet (vs. purplish red with yellow lines) stigma.

In the general appearance of flower, A. congestiflora resembles A. leucographa C.R.Lin & C.Y.Zou in Zou et al. (2017: 164), A. longhuiensis G.W.Hu, Zhi Wang & Q.F.Wang in Wang et al. (2021: 89), A. opaca Tillich (2005: 321) and A. papillata G.Z.Li in Li & Wei (2003: 382). All these species share trimerous flowers, dark violet to purple perianth with cupulate to campanulate tube, and violet to purple (at least partly) round to hexagonal stigma. However, A. congestiflora readily differs from the four species in obconoid (vs. mushroom-shaped or umbrella-shaped) pistil.

Aspidistra congestiflora is also similar to A. obtusata Vislobokov (2016: 694) in the shape of flower (including obconoid pistil), as well as in its general appearance, but differs in often finely verruculose (vs. completely smooth) perianth lobes, longer pistil (7.5–9.5 mm vs. 3.8–5.1 mm high) with (vs. without) longitudinal ridges and purple-violet (vs. white with purple spots) stigma. Notably, the protologue of A. obtusata is based on rather incomplete material: the flowers of the type specimens seem either somewhat underdeveloped (not fully opened) or withered ( Vislobokov 2016: Fig. 1 ). This should be taken into account in the comparative analyses.

Figures

FIGURE 1. Aspidistra congestiflora. A. Habit. B. Flowering plant. C. Flowers. D. Flattened leaves, cataphylls and flowers. E. Set of inflorescence bracts, abaxial (above) and adaxial side (below). F. Flower with peduncle and bracts. G, H. Flower, front and side view. I. Flower with longitudinally dissected perianth. J. Flower, longitudinal section. K. Perianth with stamens, longitudinal section. L. Flattened perianth, view from inside. M. Stamen, half-side, front and side views. N. Stigma, view from above. O, P. Pistil, side view and view from below. Q. Pistil, cross section, view from below. Photos by L. Averyanov from LA-VN 1554/5, graphic correction and design by L. Averyanov and T. Maisak.