Aspidistra linearistyla C.X.Peng & C.R.Lin, 2024

Peng, Cai-Xia, Tong, Yi-Hua, Vu, Tien-Chinh & Lin, Chun-Rui, 2024, Aspidistra linearistyla (Asparagaceae), a new species from northern Vietnam, Phytotaxa 672 (2), pp. 208-214 : 209-211

Aspidistra linearistyla C.X.Peng & C.R.Lin , sp. nov. ( Figs. 1 , 2 )

Type: — VIETNAM. Specimens prepared from cultivated plants in South China Botanical Garden, which were introduced from a limestone hill at an elevation of about 400–500 m a.s.l. around point 105.2107°E, 22.9301°N in Du Gia Town, Yen Minh County, Ha Giang Province, northern Vietnam, 3 May 2024, Cai-Xia Peng pcx0361 (holotype: IBSC!, isotypes: IBK!, VNMN!).

Diagnosis: — Aspidistra linearistyla is morphologically similar to A. cerina G.Z. Li & S.C. Tang in Li et al. (2002: 289), but clearly distinguished by its tubular perianth to 24–26 mm long with a tube white and yellow lobes, and linear pistil that is 13–14 mm long and 0.8–1 mm in diameter.

Herbs perennial, evergreen, rhizomatous. Rhizome creeping, subterete, 7–10 mm in diameter, covered with scales, internodes congested. Roots elongate. Vaginal leaves 3–4, purplish red, 1.5–9.5 cm long, enveloping base of petiole, fibrous when withered. Leaves solitary, 5–15 mm apart; petiole stiff upright, 10–19 cm long, ca. 2 mm thick, adaxially sulcate; leaf blade long elliptic, 15.5–23 cm long, 4.8–8 cm wide, green, base cuneate to broadly cuneate, inequilateral, apex long acuminate, margin entire, mid vein strongly prominent on abaxial surface. Peduncle purplish red, erect and slightly nutant, 4–5.5 cm long, ca. 2 mm in diameter, with 5–7 bracts; bracts gradually widened from below, 2–3 bracts placed near the base of the peduncle small, purplish red, 3–4 bracts placed at the middle and apex of the peduncle light green, heavily marked with purplish red at base, a bract at perianth base long ovate, 16–20 mm long, 12–15 mm wide, apex acuminate. Flowers solitary; perianth tubular, enlarged in middle lower part, 24–26 mm long, 6–lobed apically; tube white on both external and internal sides, 18–20 mm long, the widest part in the middle reaching 8–10 mm in diameter, the throat 6–7 mm in diameter; lobes yellow on both abaxial and adaxial sides, broadly ovate, subequal, 4–5 mm long, 4–5 mm wide at base, apex rounded. Stamens 6, opposite to lobes, inserted at the middle of perianth tube; anthers subsessile, oblong, 6–7 mm long, 1–1.5 mm wide, apex acuminate, reaching or just below the height of stigma, pollen yellow, abundant, often make perianth tube inside yellow. Pistil linear, white, 13–14 mm long, ovary slightly enlarged, style slender, glabrous, 0.8–1 mm in diameter, stigma truncate, not enlarged, slightly 3-lobed at margin, lober round at apex.

Phenology: —The new species was observed flowering from April to May.

Etymology:—The specific epithet refers to its slender style with a diameter less than 1 mm.

Distribution and ecology:— Aspidistra linearistyla is currently known only from Ha Giang Province, northern Vietnam. It grows under evergreen broad-leaved forests at an elevation of 400–500 m, and is not common at the type locality.

Similar species: —The new species is similar to A. cerina ( Fig.3 ) in the floral morphology, but differs by its tubular perianth 24–26 mm long (vs. 16 mm), perianth lobes yellow (vs. pale yellow), pistil linear (vs. stick), 13–14 mm (vs. 7–9 mm) long, and slender style 0.8–1 mm (vs. 2–3 mm) in diameter. Aspidistra linearistyla is also related to A. lutea Tillich (2005: 320) , but differs by perianth tube white on both sides (vs. pale yellow outside and red inside), 18–20 mm (vs. 10 mm) long, pistil linear (vs. stick), slender style 0.8–1 mm (vs. 2–3 mm) in diameter, and stigma not dilated, sightly 3-lobed at margin (vs. dilated, with three bifid arms). A detailed morphological comparison of the three species is provided in Table 1.

Figures

FIGURE 1. Aspidistra linearistyla: (A) Flowering plant; (B–C) Flowers, side view; (D) Perianth, dissected to show stamens; (E) Pistil and stigma; (F) Bracts. (Drawn by Yun-Xiao Liu from the holotype).

FIGURE 2. Aspidistra linearistyla: (A–D) Flowers; (E) Flowers, side view; (F) Flowering plant; (G) Perianth, dissected to show pistil and stamens, as well as a large amount of yellow pollen; (H) Pistil; (I) Stigma, top view; (J) Bracts. A–E, H, I: photos by C.X. Peng; F, G, J: photos by C.R. Lin.

FIGURE 3. Aspidistra cerina: (A) Flowers; (B) Plant; (C) Flower, side view; (D) Stigma, top view; (E) Flower and bud side view; (F) Perianth, dissected to show stamens and pistil; (G) Pistil; (H) Bracts. Photos by C.R. Lin.