Fimbristylis stolonifera C.B. Clarke var. cylindrica X.F. Jin & Y.F. Lu, 2017

Lu, Yi-Fei, Zheng, Chao-Zong, Chen, Jian-Min, Ye, Li-Xin, Liu, Sheng-Long & Jin, Xiao-Feng, 2017, Novelties in Fimbristylis (Cyperaceae) from Zhejiang, China: two new species and a new variety, Phytotaxa 309 (2), pp. 127-134 : 132-133

Fimbristylis stolonifera C.B. Clarke var. cylindrica X.F. Jin & Y.F. Lu , var. nov. ( Fig. 3 : E–H; Fig. 5 : A & B).

A var. stolonifera spiculis cylindricis, 8–15 mm longis, 2.5–3 mm latis, inflorescentiis simplicibus recedit.

Type: China. Zhejiang, Yongjia County, Yantan, in grasslands, elevation 800 m, 20 Jul. 1980, C. F. Zhang 7226 (holotype, HTC !; isotype, PE! ).

Perennial herbs, stoloniferous. Rhizomes creeping. Culms 4- or 5-angled, glabrous, 50–75 cm tall, with 2–4 leaves. Leaves ca. 1/2 as long as culms; blades 1.5–2 mm wide, revolute, acute at apex, sparsely pubescent on both surfaces; sheath pubescent, mouth obliquely truncate, sparsely ciliolate; ligules absent. Involucral bract 1, leaf-like, longer or nearly equal to inflorescence, sometimes with another setaceous one. Inflorescence simple, 1.8–4 × 0.8–2.2 cm. Spikelets 3–5, elongated, cylindrical-ovoid, acute at apex, 8–15 × 2.5–3 mm, 22–36-flowered. Scales ovate, reddish brown, 3–3.5 mm long, acute at apex, shiny, with 3–5 castaneous veins; stamen 3; anthers ca. 2.5 mm long. Style compressed, ca. 2 mm long, ciliate on upper margin; stigmas 2, nearly equal to style. Nutlets broadly obovoid, biconvex, pale yellow, ca. 1 mm long, transversely oblong-reticulate. Fl. and fr. in July.

Etymology —The varietal epithet refers to the cylindrical-ovoid shape of the spikelets in this variety, more elongated than in the typical variety.

Observations —Both the typical variety of Fimbristylis stolonifera C.B. Clarke (1893: 637) and the new variety have the nutlets broadly obovoid, biconvex, stigmas 2, the styles ciliate on the upper margin, and the epidermal cells irregularly 4- or 5-gonal, with undulate margins, with deeply concave surface ( Fig. 5 ).

Figures

FIGURE 3. Fimbristylis minuticulmis X.F. Jin & C.Z. Zheng, sp. nov. (A–D) and F. stolonifera C. B. Clarke var. cylindrica X.F. Jin & Y.F. Lu, var. nov. (E–H). (A) & (E) habit; (B) & (F) spikelet; (C) & (G) scale; (D) & (H) nutlet with one stamen (drawn by Xiao-Feng Jin from the holotypes).

FIGURE 5. SEM photographs of nutlets. A, B: Fimbristylis stolonifera (from C. Z. Zheng & C. F. Zhang 7916 in HTC); C, D: F. stolonifera var. cylindrica (from C. F. Zhang 7226 in HTC). A, C: whole view of nutlet (scale bar= 1 mm); B, D: surface sculpture (scale bar= 100 μm).