Aspidistra crassifila (Asparagaceae), a new species from Guangxi, China

Description

Herbs perennial, evergreen, rhizomatous. Rhizome creeping, subterete, 8–13 mm thick, covered with scales, nodes dense. Vaginal leaves 4–5, 1–14 cm long, purple-red, enveloping base of petiole, fibrous when withered. Leaves solitary, 2–5 cm apart; petiole stiff , upright, 10–40 cm long, 3–5 mm thick, adaxially sulcate; leaf blade oblong-oblanceolate, 30–60 cm long, 6–12 cm wide, base cuneate, gradually narrowed into petiole, inequilateral, apex acuminate, margin entire. Peduncle purplish red to purplish black, 2.5-6 cm long, with 4–5 bracts, bracts gradually wider from base to top of peduncle; the uppermost bract broadly ovate, purplish red or purplish black, ca. 10 mm long, ca. 12 mm wide, apex subobtuse. Flowers solitary; perianth purplish black, fleshy, campanulate, 4–6 cm in diam., 8–12 lobed apically; lobes triangular-lanceolate, 15–25 mm long and 5–10 mm wide at base, apex gradually acuminate, horizontally spreading, with appendages at base, tube 8–12 mm long, distal opening 15–20 mm diam.; stamens as many as and opposite to lobes, 6–8 mm long, inserted in the middle of perianth tube, positioned lower than stigma, filaments purplish black, enlarged, 3–4 mm wide at side view, their upper surfaces visible from above (between adaxial surface of perianth tube and margin of stigma), anthers adnate to perianth, pale yellow, oblong, 5–6 mm long, ca. 2 mm wide, connectives extended and upcurved; pistil mushroom-shaped, 2 cm long, style cylindrical, ca. 10 mm long, ca. 4 mm across, purplish red, ovary inconspicuous, stigma enlarged, ca. 10 mm high, 12–15 mm across, upper surface white with purple spots, smooth, lower surface purplish black, irregularly concaved and undulate at margin. Berry subglobose, ca. 3.5 cm across, tuberculate.

Additional specimens examined

CHINA. Guangxi Zhuang Autonomous Region, Fangcheng (City), Shiwandashan Mountains, alt. 980 m, 10 March 2005, Yan Liu L1156 (IBK); same locality, 17 January 2007, Yan Liu L1425 (IBK).

Chromosome cytology

The chromosome number of Aspidistra crassifila was determined to be 2n = 38 (Figure 3), showing a trimodal variation in chromosome length at mitotic metaphase. Among the 38 chromosomes, the first two were much longer (ca 10.5-10.6 μm) than the rest; the next 16 gradually varied, ca 3.9-7.5 μm; the remaining 20 chromosomes also gradually varied, ca. 1.9-2.8 μm long. Regardless of the chromosome length, 22 (Nos. 1, 2 and 19–38 in Figure 3B), 4 (Nos. 7, 8 and 17, 18 in Figure 3B), 12 (Nos. 3–6 and 9–16 in Figure 3B) had centromere at the median (m), submedian (sm), and subterminal (st) positions, respectively. Secondary constrictions (SC) were observed at the proximal regions of the short arms in two submedian chromosomes (arrows in Figure 3A; Nos. 19 and 20 in Figure 3B). Thus, the karyotype formula of Aspidistra crassifila is 2n = 38 = 22m^2SC+4sm+12st.

Previously, detailed cytological data were known for 42 species in the genus Aspidistra (Bogner and Arnautov, 2004; Li, 2004; Yamashita and Tamura, 2004; Qiao et al., 2008; Hou et al., 2009, Lin et al., 2010; Liu et al., 2011). Aspidistra crassifila shared a number of cytological features, namely basic chromosome numbers of x = 19, trimodal chromosome complement, the first pair of longer median chromosomes and 10th median SC-chromosomes, in common with those of the Aspidistra species previously reported (Lin et al., 2010).

Ecology

On shaded bamboo slopes in seasonal rain forests (monsoon forests).

Distribution

Currently known only from Shiwandashan Mountains, Fangcheng (City), in southern Guangxi Zhuang Autonomous Region, China (Figure 4).

Phenology

Flowering from March to May; fruits maturing in May next year.

Etymology

The specific epithet 'crassifila' is derived from its enlarged filaments.

Notes

Aspidistra crassifila (Figures 1, 2) resembles A. subrotata Y. Wan & C. C. Huang (Figure 5; Wan and Huang, 1987) in the perianth lobes triangular-lanceolate, horizontally spreading, but differs in its perianth campanulate (vs. subrotate), lobes with appendages at base (vs. without appendages, margin reflexed), filaments enlarged (vs. non enlarged), anthers adnate (vs. versatile) to parianth. Connectives extended and upcurved (vs. not extended). Also the purplish black perianth color is rather rare in Aspidistra, known only from A. renatae C. Bräuchler (Bräuchler and Ngoc, 2005), A. nikolai L.V. Averyanov & H.-J. Tillich (Tillich and Averyanov, 2008), A. atroviolacea H.-J. Tillich (Tillich, 2008), and A. pileata D. Fang & L. Y. Yu (Fang and Yu, 2002).