Aspidistra guizhouensis S.Z.He & W.F.Xu, 2015

Liu, An-Li, Xu, Wen-Fen & He, Shun-Zhi, 2015, Aspidistra guizhouensis (Asparagaceae), a new species from Guizhou, China, Phytotaxa 202 (2), pp. 149-154 : 150-152

Aspidistra guizhouensis S.Z.He & W.F.Xu sp. nov. ( Figs. 1 , 2 )

Type:— CHINA. Guizhou Province, Guiyang City , cultivated, 27 November 2005, S. Z. He & W. F. Xu 051127 (holotype, GZTM!; isotype, MO!) .

Herbs perennial, rhizome creeping, subterete, 7–9 mm thick, covered with scales. Leaf sheath 2–3, 4–15 cm, enclosing the base of leaves, fibrous when withered. Leaves solitary, 1.5–2.5 cm apart, leaf blade narrowly oblanceolate, 25–45 × 4–5 cm, apex acuminate, base gradually narrowed, distal margin denticulate, leaf blade slightly spotted with yellowwhite; petiole rigid, 15–25 cm, adaxially grooved. Peduncle 1.5–5.5 cm, bracts 2–3, broadly ovate, purple-red, 5–6 × 5–6 mm. Flower solitary, erect; Perigone urceolate, fleshly, upper half purple-red, lower half milk-white, 1.2–1.4 × 0.9–1.1 cm, 6-lobed, lobes purple-red, 2.5 mm in length, base ca. 2.5 mm wide, adaxially with 4 longitudinal keels, papillose on the inner base; tube 0.95–1.15 cm in length, 0.9–1.1 cm in diam., upper part of tube inside with papillose keels; Stamens 6, inserted at middle of perigone tube, anthers oblong, ca. 1.8 × 1 mm, subsessile; Pistil ca. 4.5 mm in length, style slender, cylindrical; stigma slightly peltate, conical in lateral view, ca. 2–2.5 mm in diam, upper surface slightly prominence at the centre and with 3 radial, bifurcate ribs, 3-lobed at margin, lobes emarginate at apex. Pollen grains oval, pollen size is 25.13–30 × 19.73–25.63 μm, the surface weakly verruculose, with wartlets of irregular sizes and shapes. Flowering in October–November.

Distribution and habitat:—The species is found in Guanling County, Anshun Prefecture, Guizhou province, China. It grows under shrubs, at an elevation of ca. 1100 m in wild. It has already been grown in cultivation.

Taxonomic relationships: — The species belongs to ser. Fimbriatae Li (2000: 215). The new species is similar to A. retusa Liang (2000: 243) and A. sichuanensis Liang (2000: 246) , The major differences lie in the shape of the leaf blade, the number of bracts, the perigone tube shape, the position of the stamens, the stigma diameter and the flowering phase.

Karyotype analysis: — The majority of Aspidistra species have a chromosome number 2n = 36 or 2n = 38. Aspidistra is essentially a dibasic genus with x = 18 and x = 19. Wang (2001) considers it reasonable to assume that the x = 19 of Aspidistra species may have been derived from that of an ancestral basic chromosome number p = 18 (see Peruzzi 2013 for the definition of p). The chromosome number of A. guizhouensis is 2n = 38, with the karyotype formula 2n = 38 = 18m + 8sm + 12st. It has eight pairs of long and medium chromosomes and eleven pairs of short chromosomes. The ratio of the longest to the shortest chromosomes is 6.71 and the karyotype symmetry is 2C. The parameters of chromosomes and the photomicrographs of somatic metaphase chromosomes and karyogram of A. guizhouensis are summarized in Table 1 and Fig. 2 (I–J) respectively. A. guizhouensis is similar morphologically to A. retusa and A. sichuanensis , but there are differences in the chromosome number and karyotype. The karyotype formula of A. retusa is 2n = 36 = 16m + 6sm + 14st (2sat) (Huang 1997), 2n = 36 = 18m + 4sm (2sat) + 14st ( Wang 1999), the ratio of the longest to the shortest chromosomes is 5.31, 7.19; The karyotype formula of A. sichuanensis is 2n = 38 = 22m (2sat) + 4sm + 12st ( Liu 2012), the ratio of the longest to the shortest chromosomes is 5.77.

Figures

FIGURE 1. Aspidistra guizhouensis (drawn by Xiang-Li Wu from the holotype,).(A) habit; (B) flower; (C) longitudinal section of flower; (D) stigma apical view.

FIGURE 2. Aspidistra guizhouensis (A) cultivated; (B) plant habit; (C) flowers in natural position; (D) longitudinal profile of a flower (showing pistil); (E) longitudinal profile of a flower (showing stamens); (F) stigma apical view; (G) stigma dorsal view; (H) flowers; (I) photomicrograph of somatic chromosomes; (J) karyogram; (K–L) pollen; (M) pollen surface ornamentation.