Gelidocalamus zixingensis W.G.Zhang, G.Y.Yang & C.K.Wang, 2023

Wang, Cheng-Kun, Guo, Rong, Guo, Chun-Ce, Yang, Guang-Yao & Zhang, Wen-Gen, 2023, Gelidocalamus zixingensis (Poaceae, Bambusoideae, Arundinarieae), a new species from southern China revealed by morphological and molecular evidence, PhytoKeys 218, pp. 29-45 : 29

Gelidocalamus zixingensis W.G.Zhang, G.Y.Yang & C.K.Wang sp. nov.

Figs 5 , 6

Diagnosis.

The new species is morphologically similar to G. multifolius , but differs by having densely white pubescence (vs. glabrous) on the culm leaf sheaths, culm leaf blades erect (vs. reflexed); apical branch sheaths much longer (vs. slightly longer or equilong) than the internodes; foliage leaf blades mesophyll (vs. notophyll).

Type.

China. Hunan, Zixing County, Lianping Township, Chengkang Village , under the forest, 25°54'1.75"N, 113°34'9.18"E, elev. ca. 594 m, 18 Oct. 2015, W.G. Zhang et al. LPC031 (holotype: JXAU!)

Description.

Rhizomes leptomorph. Culms 1.7-4.2 m, 3.5-10 mm in diameter; erect, apically slightly nodding; internodes initially covered with white pubescence, ca. 14-35 cm long, wall 0.6-1.9 mm thick; each node with a ring of white-gray appressed pubescence below sheath scar; branching intravaginal, arising from 5th node above ground, ca. 4-11 (16) branches per node; branches equal or subequal, ca. 5-30 cm long. Culm leaves sheaths persistent, 12-19 cm, culm leaf sheath abaxially with brown patches, densely white pubescent and sparsely setose near the base; culm leaf blade erect, linear-lanceolate, 0.5-2 cm long, 2 mm wide, apex acuminate, base blunt or truncate, ca.1/3 as wide as sheath apex, oral setae 2-4 on each side of the sheath apex, ca. 4 mm long; auricles absent; ligule truncate, ca. 0.5 mm high, scabrous. Branch sheath papery, white setose, without black spots, margins ciliate; sub-apical branch sheath ca. 3 cm beyond the internode. Foliage leaves usually solitary on ultimate branches; ligule truncate, ca. 1 mm, scabrous; auricles absent; oral setae 1-3 pairs straight or curved; leaf blade broadly lanceolate, usually 23.4-32.5 × 3.2-4.9 cm, lateral veins 6-8 pairs, abaxial surface basally pubescent, base cuneate and asymmetrical, margins serrulate and slightly revolute near base.

Phenology.

New shoots in October.

Etymology.

The species epithet refers to the locality of the type specimen: Zixing County, Hunan, China.

Vernacular names.

Zī Xīng Duăn Zhī Zhú (Chinese pronunciation), 资兴短枝竹 (Chinese name).

Distribution and habitat.

To date, this species has only been found under evergreen broad-leaved forest along river banks at 500-600 m in Chengkang Village, Lianping Township, Zixing County. Species growing in the surrounding area include Quercus myrsinifolia Blume, 1871 ( Fagaceae ), Aralia chinensis L., 1868 ( Araliaceae ), Eurya japonica Thunb., 1783 ( Pentaphylacaceae ), and Liriope spicata (Thunb.) Lour., 1790 ( Asparagaceae ).

Figures

Figure 5. Gelidocalamus zixingensis A habitat B new shoot C, J branch and its leaf sheath D, F, G, H culm and its leaf sheath E transection of culm and pith-cavity I leaf Sheath.

Figure 6. Gelidocalamus zixingensis A new shoot B leptomorph rhizomes and culm C-E culm and its sheath, brown patches F-H branch and its sheaths, leaf and leaf sheath.