Aspidistra quanii Aver. & V.C.Nguyen

Averyanov, Leonid V., Nguyen, Van Canh, Bui, Van Huong, Vuong, Truong Ba, Wynn-Jones, Bleddyn, Nuraliev, Maxim S., Maisak, Tatiana V., Krupkina, Ludmila I., Luu, Hong Truong, Nguyen, Khang Sinh & Nguyen, Van Khuong, 2024, Novelties in Aspidistra (Asparagaceae, Convallarioideae) with erect stems in the flora of Vietnam: A. quanii, a new species, and A. erecta, a new national record, Phytotaxa 640 (1), pp. 39-49 : 45-47

Aspidistra quanii Aver. & V.C.Nguyen , sp. nov.

( Fig. 1 & 4 )

Diagnosis: —The new species differs from the morphologically closest A. globosa in stem usually less than 3 cm tall, petiole 1.5–3.5 cm long, perianth dark purple violet to almost black outside, 1.2–1.4 cm long and wide, stamens inserted near the base of perianth tube, stigma 7.5–9.5 mm in diameter, with 12 equally prominent longitudinal ridges, and smooth fruit surface.

Type: — VIETNAM. Lam Dong Province: Lam Ha District, Hon Nga Mountain , evergreen broad-leaved forest at elevation of about 1200 m a.s.l., collected in nature by Ly Ngoc Quan, s.n., rare. Herbarium and photos prepared from these plants cultivated in Buon Ma Thuot Town (Dak Lak Province) by Nguyen Van Canh, flowers globular, dark violet to almost black, 13 June 2023, Nguyen Van Canh, AL2461 (holotype LE LE01253756 https://en.herbariumle.ru/?t=occ&id=210950, analytical photos of living plants used for the preparation of the type specimen LE LE01124735 https://en.herbariumle.ru/?t=occ&id=208243).

Etymology: —The species is named after its discoverer, Mr. Ly Ngoc Quan.

Description:—Plant herbaceous, terrestrial, perennial. Stem erect, stout, (1.5)2–2.5(3) cm tall (or longer?), (4)4.5–5(5.5) mm in diameter, with numerous cataphylls and (2)3–4(5) individually arranged (not tufted) foliage leaves, supported by (2)3–4 densely adpressed prop roots. Roots straight, rigid, white to light gray, shortly tomentose, (6)8–12(14) cm long, (2.5)3–3.5(4) mm in diameter. Cataphylls white to light gray, during anthesis completely disintegrated into linear fibrous remnants (1)1.5–3(3.5) cm long, completely covering stem. Leaves distinctly petiolate; petiole suberect, (1.5)2–3(3.5) cm long, (1.8)1–1.5(1.8) mm in diameter, adaxially canaliculate, at the base slightly swollen; leaf blade arcuate, leathery, narrowly ovate, (7)8–11(12) cm long, (1.8)2–3(3.5) cm wide, acute to shortly acuminate, at base cuneate to unequally roundish, uniformly grassy green adaxially, light pale green abaxially, with prominent midvein and indistinct secondary veins more or less parallel to midvein. Peduncle erect to suberect, (3.5)4– 5.5(6) mm long, 1.6–1.8 mm in diameter in sicco (2–2.5 mm when fresh), white to light greenish, with 4–6 bracts. Bracts widely ovate, (2.5)3–4(4.5) mm long and wide, white to yellowish white finely speckled with small purple dots, irregularly dissected along margin. Flowers solitary at top of peduncles, erect. Perianth mostly consisting of a tube, with 6 very small lobes at top, spherical to broadly ellipsoid, (1.2)1.3(1.4) cm long and wide, uniformly dark purple violet to almost black outside and inside, smooth and somewhat glossy outside, finely papillose inside, apically with orifice 1.8–2.2 mm in diameter between lobes; lobes horizontal (pointing toward the orifice), with overlapping bases, broadly triangular, obtuse, (1.6)1.8–2(2.2) mm long, (1.8)2–2.2(2.4) mm wide. Stamens 6, inserted slightly above the base of perianth tube, at the same radii with perianth lobes; anthers sessile, bean-shaped, 1.4–1.6 mm long and wide, light yellowish to almost white, introrse. Pistil with style much shorter than stigma; style cylindrical, less than 1 mm long, 1.4–1.6 mm in diameter, dark purple; stigma widely obconoid, (2.4)2.6–3.8(4) mm tall, (7.5)8–9(9.5) mm in diameter, dark purple except for upper surface, with 12 equal very prominent narrow longitudinal ridges, upper surface flat, star-shaped, papillose, dull yellowish flushed with purple, with thin upright, dark purple margin and three dark purple, prominent broad radial ridges. Ovary superior, small and inconspicuous. Unripe fruits upright on erect peduncles, globular, 4–5 mm in diameter, grassy green, with smooth surface.

Ecology and phenology: —Evergreen broad-leaved forests on granite at elevations of about 1200 m a.s.l. Flowers in May–June.

Distribution: — Vietnam: Lam Dong Province (Lam Ha District). The species is likely to be endemic to a very restricted area of Hon Nga Mountain.

Conservation status: —The species is currently known from a single location where it was observed as an occasional plant scattered in understory of a primary forest in an expected area of surely less than 100 km 2. This area has no legal protection status and suffers from uncontrolled selective logging, which reduces the habitat quality. Following the formal criteria B1ab(iii) + 2ab(iii) of the IUCN (2023), we preliminarily assign the conservation status of this species as Critically Endangered (CR).

Notes: — Aspidistra quanii belongs to a distinct group of species that is characterized by erect stem supported by prop roots and globular or obconoid chamber-like perianth with short or missing lobes and narrow orifice. This group is confined to Laos, Vietnam and S Guangxi. It includes A. brachypetala C.R.Lin & B.Pan in Pan et al. (2020: 195), A. globosa , A. khangii Averyanov & Tillich (2014: 753 ; Averyanov et al. 2019a), A. locii Arnautov & Bogner in Bogner & Arnautov (2004: 203; Averyanov et al. 2019a) and A. micrantha Vislobokov & Nuraliev in Vislobokov et al. (2019c: 291). In addition, A. phongdiensis D.Dien, T.A.Le & Vislobokov in Chinh et al. (2023: 65) possibly belongs here, because the available images of this species suggest presence of a very short vertical stem that bears flowers (although the description provided in the protologue states that the vegetative shoot is represented only by an epigeous creeping rhizome). Among them, A. quanii is most close to A. globosa endemic to Kon Ka Kinh National Park in Gia Lai Province of Vietnam, from which it readily differs in stout stem probably not more than 3 cm tall (vs. slender stem to 40–50 cm tall), petiole 1.5–3.5 cm (vs. 5.5–11 cm) long, perianth outside dark purple violet to almost black (vs. light greenish becoming grayish-brown with age), 12–14 mm long and wide (vs. 6.5–10 mm long, 6.7–8.4 mm wide), with horizontal (vs. erect to slightly recurved) lobes, stamens inserted near the base (vs. at the middle) of perianth tube, anthers 1.4–1.6 mm (vs. 1.5–2 mm) long, pistil less than 1/2 of the perianth chamber length (vs. slightly longer than 1/2 of the perianth chamber length), stigma 7.5–9.5 mm (vs. 5–6 mm) in diameter, with 12 equally prominent longitudinal ridges (vs. 6 prominent longitudinal ridges alternating with 6 somewhat less prominent ridges), and smooth (vs. tuberculate or verruculose) fruit surface. The most important differences of the new species from the rest of the species group outlined above include the horizontal perianth lobes, stamens inserted near the base of perianth tube and obconoid stigma.

Figures

FIGURE 1. Distribution map of Aspidistra erecta, A. globosa and A. quanii (the map is not aimed to show countries in their entire borders).

FIGURE 4. Aspidistra quanii. A. Flowering plant under cultivation. B. Prop roots at base of aerial stem. C. Upper part of stem with flowers, side and front view. D. Flowering plant. E. Leaves, abaxial and adaxial side. F. Flowers, side, front view and view from below. G. Sagittal section of flower with intact pistil. H. Sagittal sections of perianth, showing stamens. I. Anthers. J. Peduncle with bracts and pistil, side view. K. Pistil, side view. L. Stigma, view from above. M. Stigma, view from below. N. Sagittal sections of peduncle and pistil. Photos by Nguyen Van Canh, made from the specimen used for the holotype preparation (Nguyen Van Canh, AL2461), correction and design by L. Averyanov and T. Maisak.