Carex planiscapa Chun & How (1958: 82)

Jin, Xiao-Feng, Cen, Jia-Meng, Hahn, Marlene, Lu, Yi-Fei & He, Jin-Jing, 2015, Notes on Carex (Cyperaceae) from China (II): a taxonomic revision of sect. Radicales (Kük.) Nelmes, Phytotaxa 217 (2), pp. 117-132 : 127

(6) Carex planiscapa Chun & How (1958: 82) . Type:— CHINA. Hainan: Baishan , Mount. Wuzhi, 9 Dec 1954, Hainan Exped. 621 (holotype, IBSC; isotype, IBK!, PE!) ( Figure 5 : M–R) .

Perennial herbs. Rhizomes short. Culms 8–20 cm tall, densely caespitose, ca. 1 mm thick, compressed trigonous, soft and smooth. Leaves at least twice as long as culms, flat, 3.5–7 mm wide, soft, glabrous, scabrous on margins, with brown persistent sheaths at base. Involucral bracts scale-like. Spikes 1 or 2, androgynous, remote, cylindrical, 5–10 mm long, 2–3 mm wide; staminate part of spike longer than pistillate part, rarely equal in length, densely flowered, pistillate part shorter than staminate ones, with a few pistillate flowers. Staminate scales oblong, 1.5–2 mm long, pale green, obtuse at apex, green 1-veined costa. Pistillate scales broadly ovate, yellowish green, 1.5–2 mm long, obtuse at apex, green 1-veined costa. Perigynia pale green, ellipsoid-ovoid, compressed trigonous, 2–3 mm long, sparsely pubescent on upper part, later glabrescent, 2-veined laterally and thinly veined, nearly rounded at base, ciliate at margins, inconspicuously beaked at apex; orifice obliquely truncate. Achenes ellipsoid, trigonous, dark brown at maturity, sides slightly concave, ca. 2 mm long, cuneate at base, shortly beaked at apex; style cylindrical, thickened, densely brown granular-punctate; stigmas 3.

Additional specimens examined:— CHINA. Hainan: Baoting, Xinglong, K. C. How 73586 (IBK, PE). Without precise locality, N. C. Chun 44442 (IBK).

Note:— This species is characterized by compressed trigonous culms, scale-like involucral bracts, cylindrical spikes, perigynia that are inconspicuously beaked at the apex, and densely granular-punctate styles.

Figures

FIGURE 5. A–E: Carex tsaiana F. T. Wang & Tang ex P. C. Li. (A) habit; (B) staminate scales; (C) pistillate scale; (D) perigynium; (E) achene. F, G: Carex daxinensis Y.Y. Zhou & X. F. Jin. (F) perigynium; (G) achene. H–L: Carex tsoi Merr. & Chun. (H) habit; (I) staminate scales; (J) pistillate scale; (K) perigynium; (L) achene. M–R: Carex planiscapa Chun & How. (M) spike; (N) transverse section of culm; (O) staminate scales; (P) pistillate scale; (Q) perigynium; (R) achene. (A–E drawn from H. T. Tsai 60957 in KUN, F, G from X. F. Jin & Y. Y. Zhou 3026 in HTC, H–L from X. F. Jin 2995 in HTC; M–R from Hainan Exped. 621 in IBK; drawn by Xiao-Feng Jin).