Aspidistra xichouensis Lei Cai, Z.L.Dao & G.W.Hu, 2020

Cai, Lei, Pan, Bo, Lin, Chun-Rui, Dao, Zhi-Ling & Hu, Guang-Wan, 2020, Aspidistra xichouensis (Asparagaceae), a new species from the karst region in southeastern Yunnan, China, Phytotaxa 439 (2), pp. 143-149 : 145-148

Aspidistra xichouensis Lei Cai, Z.L.Dao & G.W.Hu sp. nov. ( Figs. 1 & 2 )

Diagnosis: — Aspidistra xichouensis is similar to A. minutiflora , A. graminifolia and A. cylindrica in the shape of leaf blade and the size of flowers, but it can be easily distinguished from them mainly by leaves with conspicuous petiole 8–20 cm long (vs. leaves sessile or with inconspicuous petiole), upright (vs. curved down) peduncle, erect (vs. nodding) flowers, slightly urceolate perianth tube reaching its max width at the middle (vs. urceolate, cupulate or campanulate tube wider at the base or at the mouth), mostly 4 (vs. mostly 6) perianth lobes, and mostly 4 stamens inserted near the middle of the perianth tube (vs. mostly 6, inserted at the base of the perianth tube) (see Table 1, Figs. 1–3 ).

Type: — CHINA. Yunnan, Xichou County, Dongma Township, Laonong Village, under forest in Limestone area, 23° 24’ N, 104° 55’ E, alt. 1335 m, 21 March 2019, Lei Cai CL 221 (holotype KUN!, isotypes KUN! HIB!).

Chinese name: —Xī Chóu Zhī Zhū Bào Dàn (ŮĦÞǠ抱&).

Description: —Terrestrial perennial herb, 40–70 cm tall. Rhizome creeping, subterete, 6–10 mm in diameter, covered with scales, densely nodose. Leaf sheaths brown, 3−8 cm long. Leaves mostly solitary, occasionally 2-tufted; petiole stiff, 8–20 cm long, 3–4 mm thick, adaxially sulcate; leaf blade lorate to lorate-oblanceolate, 30–50 cm long, 1.2–2.5 cm wide, dark green, base cuneate, gradually tapered into petiole, margin entire, apex acuminate. Peduncle upright, stiff, white, 1.5–4.0 cm long, with 2–4 bracts; bracts gradually widening toward the apex of the peduncle, the uppermost two adpressed to the bottom of flower, broadly ovate-cucullate, white with purple spots, 8–10 mm long, 6–9 mm wide, apex acuminate. Flower solitary at the top of peduncle, tetramerous (dimerous); perianth urceolate, fleshy, 1.0– 1.3 cm long, 0.6–0.9 cm wide; tube slightly urceolate, 6–9 mm long, 7–8 mm wide, ca. 1 mm thick, outside white, usually with purple-red spots, inside white in lower part and blackish purple in upper part; lobes 4 (rarely 5 found in cultivated condition in Guilin), ovate-triangular, unequal, 4–5 mm long, 3–4 mm wide, yellow, outside usually with purple-red spots, apex blunt and inflexed. Stamens 4 (rarely 5), opposite to perianth lobes, inserted on the perianth tube at ca. 3 mm (2/5) from the base; filaments ca. 1 mm long, white; anthers yellow, ca. 1.8 mm long, 2 mm wide, lower than stigma. Pistil subcylindric, somewhat dumbbell-shaped, 6–8 cm long; ovary subglobose, ca. 2 mm in diameter, sometimes inconspicuous; style clavate, ca. 3 mm long; stigma rectangular or square, 2–3 mm in diameter, white with purple margin. Fruit globose, ca. 1.3 cm in diameter, yellow-green, with blackish purple verruca on surface.

Distribution and ecology: —Two populations of Aspidistra xichouensis were found in Xichou County,southeastern Yunnan, China. Fifteen clumps of Aspidistra xichouensis were discovered in one locality in Laonong, ca. 10 km far from the first population discovered in Dalongshai, which hosts ca. 10 clumps. They occur under evergreen broadleaved forests in a limestone area. Living plants from one population were transplanted at Wuhan Botanical Garden (30°32' N, 114°25' E, alt. 30 m) in 2013, and some of them were then moved to Guilin Botanical Garden (25°05' N, 110°17' E, alt. 150 m) in 2016. Plants in Wuhan did not flower after the transplant, whereas those planted in Guilin flowered in 2018 and 2019. This species is supposed to prefer a warm, humid climate in tropical and subtropical regions.

Phenology: —The new species flowers from March to April and bears immature fruits in March.

Etymology: —The specific epithet refers to the type locality in Xichou County, Yunnan Province, China.

Similar species:— Aspidistra xichouensis is morphologically close to A. minutiflora (see Figs. 2 and 3 ), which occurs in southern China, particularly in Guangdong, Guangxi, Guizhou, Hainan, Hong Kong and Hunan regions. It also shows affinities with A. graminifolia and A. cylindrica , both of which are distributed in Vietnam. These species share long and narrow (lorate or linear) leaves and relatively small flowers. The new species can easily be distinguished from the three related ones by several characters listed in Table 1. Aspidistra minutiflora usually has purple spots on the outside of the perianth ( Stapf 1903, Liang et al. 2000, Li 2004), however, the plants in Kunming Botanical Garden (originally introduced from Guangxi) were devoid of such spots on the perianth ( Fig. 3 ).

Additional specimens examined (paratype):— CHINA. Yunnan, Xichou County, Fadou Township, Dalongshai Village, under forest in Limestone area, 23°33’ N, 104°51’ E, alt. 1300 m, 10 June 2013, G.W. Hu HGW-00973 (HIB!)

Figures

FIGURE 1. Aspidistra xichouensis Lei Cai, Z.L.Dao & G.W.Hu. A. Habit. B. Lateral view of flower with bracts. C & D. Longitudinal section of flower (showing stamens and pistil). E. Lateral view of pistil. F. Stigma, frontal view. G. Fruit. Drawn by Xuan-Lin Zhu.

FIGURE 2. Aspidistra xichouensis Lei Cai, Z.L.Dao & G.W.Hu. A. Habitat in Xichou County, Yunnan Province. B & C. Inflorescence. D. Lateral view of flower with bracts. E. Stigma. F. Fruit. G. Frontal view of flower. H. Longitudinal section of flower (showing stamens and pistil). I. Longitudinal section of young fruit. All photographs were taken by Lei Cai.

FIGURE 3. Aspidistra minutiflora Stapf. A. Habitat in Kunming Botanical Garden. B & C. Inflorescence. D. Lateral view of flowers. E & G. Longitudinal section of flower (showing stamens and pistil). F. Front view of flower. H. Lateral view of pistil. I. Stigma. All photographs were taken by Lei Cai.