Cladopus yinggelingensis Q.W.Lin, G.Lu & Z.Y.Li, 2016

Lin, Qin-Wen, Lu, Gang & Li, Zheng-Yu, 2016, Two new species of Podostemaceae from the Yinggeling National Nature Reserve, Hainan, China, Phytotaxa 270 (1), pp. 49-55 : 50-51

Cladopus yinggelingensis Q.W.Lin, G.Lu & Z.Y.Li , sp. nov., Fig. 1 : A–L; Fig. 3 : A–F.

Ab C. doianus et C. nymanii radicis 4–8 mm latis, bracteis 15–20, filamentis ovarium aequilongis, stigmatibus obtriangularibus differt.

Type: — CHINA. Hainan: Baisha, Yinggeling National Nature Reserve, Daoyin village, elevation 365 m, 109°20’50.48”E, 19°0’12.95”N, 24 March 2015, Q. W. Lin, X. Y. Mu & G. Lu 1176 (holotype PE, isotype PE).

Roots creeping, adhering to rock surface, ribbon-like, alternately branched, 4–8 mm wide, dark green and turning offwhite when dry, with tufts of leaves on dorsal surface at sinuses of root branching. Leaves 4–6 per tuft, linear, flat, apex acuminate, 4–6 mm long. Floriferous shoots on dorsal surface at sinuses of root branching, solitary, erect, 3–5 mm long. Bracts 15–20, 1–2 mm wide, imbricate, digitate; lobes 5–10, linear, 0.2–0.5 × 0.1–0.2 mm, hard, rough, with silica on surface. Spathella enclosing young flower, spheroidal, mucronate. Flowers solitary, terminal; pedicels short, ca. 1 mm long. Tepals 2, on each side of stamen, linear, 1–1.5 mm long. Stamens 2 (filaments connate as one), rarely 1, 1.3–1.5 mm long, as long as, or slightly longer than, pistil; filaments very short, compressed, 0.5–0.7 mm long; anthers 4, rarely 2, elliptic, yellow, ca. 0.8 mm long. Ovaries single, sessile, green, globose, 1–1.5 mm in diam.; locules 2, with 2 nearly vertical, purple-flushed grooves; stigmas 2, forked at base, red, ca. 0.5 mm long, bent towards anthers, widened, obtriangular; ovules ellipsoidal, 30–40 per locule, borne on whole placenta surface. Stalks of capsule 1–2 mm long. Capsules brown, globose, ca. 1.5 mm in diam., smooth, 2-valved when dry; seeds small, brown, compressed, narrowly ovoid, 0.3–0.4 mm long.

Distribution and habitat: — Cladopus yinggelingensis is only known from the type location, Hainan, China. It grows on rocks in valley streams with unpolluted water.

Phenology: —Flowering and fruiting in February–April.

Comparison: — Cladopus yinggelingensis is similar to C. doianus in many aspects, but the later species has narrower roots (2–4 mm wide), fewer bracts (10–12) and taper deltoid stigmas. C. nymanii can be distinguished from C. yinggelingensis by its flowering shoots to 10 mm long, stamens to 2.5 mm long and distinctly longer than the ovaries. C. pierrei also shares some characters (tufts of leaves, flowering shoots) with C. yinggelingensis , but differs form it by its narrower roots (1–4 mm wide), longer pedicels or capsule stalks (up to 5 mm) and distinctly forked stamens. C. austrosinensis , a species also from Hainan, is distinctly different from C. yinggelingensis by its narrow (to 1 mm wide), subcylindrical roots, and fewer (8–10) bracts, and is widely distributed in Guangdong, Hainan and Hong Kong, but not sympatric with C. yinggelingensis . Moreover, other known congeneric species can easily be distinguished from the new one by their characteristics of roots, flowering shoots, bracts, stamens and stigmas ( Table 1).

Figures

FIGURE. 1. A–L. Cladopus yinggelingensis (From the holotype and field images). A. Roots. B. Floriferous shoot with young flower enclosed by Spathella. C. & D. Flowering shoots. E. & F. Bracts. G. Spathella. H. Ovary with ovules. I. Flower. J. Stamens with 2 tepals. K. Stigmas. L. Fruiting shoot.

FIGURE. 3. A–F. Cladopus yinggelingensis. A. Roots. B. Flowering shoots. C. Fruiting shoots. D. tufts of leaves. E. bubbles covering the anthers and stigmas. F. Pollens. G–L. T. daoyinensis. G. Roots with flowering shoots. H. Flowers with unopened stamens. I. Flowers with withered stamens and mature stigmas. J. flowering shoots and vegetative ramuli. K. Fruits. L. Pollen.