Carex thibetica Franch. var. angustifolia X.F.Jin & Y.F.Lu, 2022

Lu, Yi-Fei & Jin, Xiao-Feng, 2022, Notes on Carex (Cyperaceae) from China (VIII): five new species and a new variety from southern and south-western China, PhytoKeys 188, pp. 31-47 : 31

6. Carex thibetica Franch. var. angustifolia X.F.Jin & Y.F.Lu var. nov.

Figure 5A-E

Latin diagnosis.

A var. Carex thibetica differt foliis 4-6.5 mm latis, spicis staminatis 1.5-2 mm latis, utriculis longioribus 9-12 mm longis.

Type.

China. Hunan: Dongan, Shunhuangshan Forestry Park, Butterfly Valley , by stream under forest, alt. 680 m, 21 May 2017, H. Wang 1434 (holotype: ZM; isotypes: ZJFC, ZM) .

Rhizomes short or elongate, woody, stiff, with many brown fibrous roots. Culms lateral, loosely caespitose, 20-55 cm tall, obtusely trigonous, smooth, glabrous. Leaves basal, slightly shorter to longer than culms; blades flat, 4-6.5 mm wide, coriaceous, apex acuminate, lower surfaces and margin slightly scabrous. Bracts shortly leaf-like, shorter than spikes, sheathed; sheaths 1.5-2.5 cm long. Spikes 3 or 4 in a racemose; terminal spike staminate, narrowly linear-cylindrical, 3.5-8 cm long, 1.5-2 mm wide, base with 4-8 cm long peduncles; lateral spikes androgynous, staminate part longer than pistillate part, cylindrical, 4-9 cm long, 7-10 mm wide, 8-20-flowered (pistillate), with peduncles exserted from sheaths. Staminate glumes lanceolate or lanceolate-oblong, pale yellow-green, 7-7.5 mm long, apex acuminate, with pale brown 1-veined costa. Pistillate glumes narrowly ovate, pale green-brown or brown, 8.5-11 mm long, apex acuminate, with green or brown-green 3-veined costa. Utricles yellow-brown or brown, rhombic-ovoid, obtusely trigonous, 9-12 mm long, slightly longer than pistillate glumes, nearly erect or obliquely patent, distinctly thinly veined, sparsely puberulent on upper part, apex abruptly contracted into a 4.5-6 mm long beak, orifice 2-lobed with long teeth, margin barbate. Nutlets tightly enveloped, brown, rhombic-ovoid, trigonous, 3-4 mm long, base with a ca. 0.5 mm long curved stipe, apex abruptly contracted into a coiled short beak, with 3 angles constricted at middle and sides concave above and below; style base slightly thickened; stigmas 3.

Etymology.

The variety epithet ‘angustifolia’ refers to the narrower leaves (4-6.5 mm wide) than the typical variety (6-17 mm wide).

Phenology.

Flowering and fruiting is from mid-April to late May.

Additional specimens examined.

China. Hunan: Dongan, Shunhuangshan Forestry Park, Butterfly Valley , by stream under forest, alt. 680 m, 21 May 2017, H. Wang 1433 (ZJFC, ZM); the same locality, alt. 730 m, 19 Apr 2018, W.J. Chen 2394 (HTC, ZM), 2395 (ZJFC, ZM), 2396 (ZJFC, ZM). Suining, Huangsang Natural Reserve , Quyougu, under forest, alt. 755 m, 26 Apr 2014, J.J. Zhou & Z.P. Song 1404223 (CSFI); the same locality, Banchong, under forest, alt. 906 m, 2 May 2014, J.J. Zhou & Z.P. Song 1405022 (CSFI) .

Conservation status.

Least Concern (LC). The new variety is known from four localities in southern Hunan Province, but two of them are seriously disturbed by local people ( IUCN 2019).

Notes.

The new variety differs from the typical variety in having the leaves narrower, 4-6.5 mm in width, terminal staminate spikes 1.5-2 mm in width and utricles longer, 9-12 mm long. It differs from Carex thibatica var. pauciflora in having lateral spikes with densely 8-20 pistillate flowers and utricles longer, 9-12 mm long.

Figures

Figure 5. Carex thibatica var. angustifolia var. nov. A habit B staminate glume C pistillate glume D utricle E nutlet (Drawn by Hong Wang; based on holotype: H. Wang 1434 in ZM).