Rohdea medogensis H. Z. Feng & Q. W. LIN, 2022

Feng, Hui Zhe, Ren, Yong Zhu Ci, He, Xuan, Han, Qing Xiang & Lin, Qin Wen, 2022, Rohdea medogensis (Asparagaceae), a new species from southeast Tibet, China, Phytotaxa 542 (1), pp. 90-94 : 91-92

Rohdea medogensis H. Z. Feng & Q. W. LIN , sp. nov. ( Figs. 1 & 2 )

Type:— CHINA. Tibet Autonomous Region: Linzhi, Motuo county , alt. 1837 m, 16 January 2022, Q. W . Lin 2022–0047 (holotype, PE!) .

Diagnosis:—This species is similar to R. verruculosa ( Chen 1987: 69) Tanaka (2003: 332) , but differs mainly by bracts 3 per flower, with several sterile bracts apically; outer bract ca. 4.5 cm long, ca. 3 mm broad; perianth globular; lobes shorter ca. 2.0 mm long, margin lacerated, apical subacut; the top of annular appendage margin lacerated, 2 mm above the the top of perianth tube; stigma bend, without lobed; style conspicuous; ovary globose or subglobose, askew; berry and seed ellipsoid, askew.

Description:—Chamaephytic herb. Rhizome cylindrical, usually erect, to 2.5 cm in diameter, 5–6 cm long. Roots fibrous, to 6 mm in diameter. Stem (aerial part) short, up to 5 cm long. Leaves equitant, narrowly oblanceolate, narrowly elliptic or lorate, acute to acuminate at apex, tapering gradually to petiole-like base, subcoriaceous, 20–55 cm long, 3–8 cm wide. Peduncle ca. 3 cm long. Spike cylindrical or ellipsoid, with ca. 6 flowers, ca. 5 cm long, with several sterile bracts apically. Bracts 3 per flower, often minutely denticulate at margin, herbaceous or membranous; outer bract 1, borne slightly below flower, exceeding flower, lanceolate or narrowly deltoid, acute, 3–5 cm long, 2– 3 mm broad; inner bract (bracteole) 2, subulate, to 7 mm long, 1.5–2 mm broad, with several sterile bracts apically. Perianth globular, green, turning yellow or orange with age, 8–10 mm across; lobes deltoid-ovate, lacerated, often abaxially with verruculose long margins, 2–3 mm long, 3–4 mm wide; tube cupulate, 2.5–4 mm long, at orifice of tube developing annulus (or annular ledge) appendages, 1–1.5 mm broad. The annulus appendages and tube formed a capsule chamber that encloses the pistil, and there is only a small hole in the center, diam. 1mm, lacerated. The stamens are above the annulus appendages. Anther oblong or ovate, 0.8–1.5 mm long, connectives sometimes corniculate dorsally, cornicle up to 1.5 mm long; filaments incurved, 1–2 mm long, inserted in upper part of perianth tube, decurrent parts lamellate, dilated below, united with adjacent ones in lower part of tube. Pistil ca. 5 mm long; stigma bend and not lobbed; style columnar, conspicuous, 3.5–5.5 mm long; ovary globose or subglobose, askew, 2.5–3.0 mm in diam. Berry ellipsoid, askew, ca. 2.5 cm long, scarlet at maturity. Seed ellipsoid, askew, ca. 1.0 cm in diam.

Etymology:—The new species from Motuo (=Medog) country, we therefore give the epithet Rohdea medogensis .

Distribution:—This new species is currently known only from Motuo, Linzhi, Tibet, China.

Taxonomic relationships:—The comparisons with the known species of Rohdea indicates that R. medogensis is similar to R. verruculosa , R. annulata (Li & Huang in Huang & Li 1990: 51) Yamashita & Tamura (2004: 369) and R. harderi Tanaka, Hannon & Averyanov in Tanaka et al. (2018: 2) by stamens enclosed annulus appendage or stamens situated outer annulus appendage while other species as R. uropetala Handel-Mazzetti (1920: 272) , R. lichuanensis (Yang, Wu & Peng in Wang et al. 1991: 40) Yamashita & Tamura (2004: 369) and R. emeiensis ( Zhu 1982: 271) Tanaka (2003: 332) possess annulus appendage enclosed stamens or stamens situated inner annulus appendages. The new species more similar to R. verruculosa because of the lobes abaxially with verruculose in these two species. R. medogensis differs from R. verruculosa by the characters of the short spike and peduncle. R. medogensis with several sterile bracts apically and it also has 3 fertile bracts per flower and the outer bract exceeding the flowers. In R. medogensis the perianth globular; lobes deltoid-ovate, very short, apical portion subacute, in R. verruculosa perianth subcampanulate, lobes ovate, apex cuspidate. And the style in R. medogensis was very conspicuous, ovary askew and stigma was bend and not lobed, but in R. verruculosa the style was very short and ovary globose, the stigma was straight and 3-lobed. The floral traits of the two species are compared in Table 1 .

Figures

FIGURE 1. Rohdea medogensis. A. Habit. B, C & D. Inflorescence. E. Flower and bracts. F. Flower in longitudinal section. G. Flower with lobes removed, top view. H. Half of flower in longitudinal section. I. Half of flower without pistil in longitudinal section. J. Pistil. K. Perianth with a stamen. L. Leaf blade.

FIGURE 2. Rohdea medogensis. Originally collected by Feng Hui Zhe and Gong Zheng in Tibet, Medog County, Beibeng, ca.1000 m. Cultivated in Zaozhuang University. A. Habit. B. Inflorescence and fruits. C. Fruits. D. Seeds. E & F. Pistils, E. Top view; F. Side view.