Carex longipetiolata Q.L. Wang, H.B. Yang & Y.F. Deng, 2012

Wang, Qing-Long, Yang, Hu-Biao, Deng, Yun-Fei, Wang, Zhu-Nian & Liu, Guo-Dao, 2012, Carex longipetiolata (Cyperaceae), a new sedge from Hainan, China, Phytotaxa 75 (1), pp. 65-69 : 66-68

Carex longipetiolata Q.L. Wang, H.B. Yang & Y.F. Deng , sp. nov. ( Figs. 1 , 2 )

The new species is similar to C. saxicola Tang & F.T. Wang , but apparently differs from the latter by having culms 5–20 cm long (instead of up to 60 cm), petioles 5–10 cm long (not sessile), leaf blades 1–1.5 cm (not 0.8–1) cm wide, terminal male spike subsessile (not with a peduncle 3–5 cm long), and lateral spikes entirely female (not androgynous).

Type:— CHINA. Hainan: Lingshui Xian, Diaoluo Shan , moist place in the valley, 520 m., 24 August 2010, Wang Qinglong & Yang Hubiao 18063 (holotype IBSC!, isotype TCGRI!) .

Perennial; rhizome short, ligneous. Culms usually solitary, central, 5–20 cm tall, rigid, trigonous, scabrous above. Leaves surpassing culm; petiole ca. 5–10 cm long; leaf blades green, ensiform, 1–1.5 cm wide, flat, apex acuminate, margins scabrous upward, base gradually narrowed into the petiole. Involucral bracts surpassing inflorescence, sheathing, sheath ca. 0.5–1 cm long, chartaceous, green. Spikes 3 or 4, approximate, all sessile; terminal spike staminate, linear-cylindrical, 1.5–4 × 0.3 cm; lateral spikes pistillate, cylindrical, 1–2 × ca. 0.7 cm. Staminate glumes oblong-lanceolate or lanceolate, ca. 6.5 mm long, pale green, 3-veined; stamens 3, filaments slightly shorter than the glumes. Pistillate glumes pale green, ovate or deltoid-ovate, 5–6 mm, membranous, subglabrous, many-veined, middle vein excurrent into a short awn for ca. 1.5 mm. Perigynia longer than the glumes, ovate-lanceolate, 7–8 mm long, sparsely hispid or subglabrous, manyveined, base cuneate, apex gradually narrowed into a scabrous long beak for 2–3 mm, orifice straight, 2- toothed, teeth up to 1 mm; stigmas 3, hispid. Nutlets brown to dark brown, but beak and angles yellowish white, tightly enveloped by the perigynium, elliptic-rhomboid, ca. 5.5 mm long, trigonous with angles constricted at the middle, apex abruptly contracted into a narrowly cylindric beak of ca. 2 mm, beak expanding into a discoid-annulate orifice; persistent style ca. 2.5–3 mm long, base thickened.

Distribution and Habitat:— Carex longipetiolata is known only from Diaoluo Shan Nature Reserve, Hainan, China. It grows in moist forest at altitudes of 500– 600 m.

Phenology:—The new species was observed in flower and fruit from April to August.

Etymology:—The species epithet was derived from the Latin “ longipetiolata ”, meaning “having a long petiole”.

Conservation status: — Carex longipetiolata was only collected in 2010 and 2011 respectively in two populations from its type locality, Diaoluoshan Natural Reserve, which is covered about 300 km 2 and is well protected. So, C. longipetiolata is classified as Least Concern (LC) ( IUCN 2001) according to the guidelines for using the INCN Red List Criteria ( IUCN 2011: 59).

Relationships.—The new species is placed in Carex sect. Rhomboidales because its trigonous nutlets that are constricted in the middle part and mitrate at the apex. In Hainan Island, only two species of C. sect. Rhomboidales, C. harlandii Boott (1860: 87 , t. 255) and C. saxicola , were recorded previously. C. longipetiolata can be easily distinguished from them by its lateral spikes entirely female (not androgynous). C. longipetiolata is closely related to C. saxicola in the characters of pistillate glumes glabrous and aristate at apex, the glabrous perigynia longer than the pistillate glumes and the straight nutlets, but differs from the latter in longer culms and petioles and subsessile spikes ( Dai et al 2000, 2010, Deng 2007).

Additional specimen examined (Paratype):— CHINA. Hainan: Lingshui Xian, Diaoluo Shan Nature Reserve , 950 m, 11 May 2011, Wang Qinglong & Huang Mingzhong 1131107 ( IBSC!, TCGRI!) .

Figures

FIGURE 1. Carex longipetiolata. A. Habit. B. Inflorescence. C. Staminate glume. D. Pistillate glume. E. Periginia. F. Nutlet. G. Stigmas. Photographs by Q. L. Wang.

FIGURE 2. Carex longipetiolata. A. Habit. B. Inflorescence. C. Pistillate glume. D. Perigina. E. Opened perigina. F. Nutlet. Drawn by Yun-xiao Liu based on Wang & Yang 18063 (IBSC).