Indosasa fimbriligulata N. H. Xia, Z. Y. Niu & Y. H. Tong, 2025

Niu, Zheng-Yang, Bai, Lin, Tong, Yi-Hua & Xia, Nian-He, 2025, Indosasa fimbriligulata (Poaceae, Bambusoideae), a new bamboo species from Guangxi, China, PhytoKeys 265, pp. 209-221 : 209-221

Indosasa fimbriligulata N. H. Xia, Z. Y. Niu & Y. H. Tong sp. nov.

Figs 2 , 3 , 4

Type.

China • Guangxi Zhuang Autonomous Region: Fangchenggang City, Naliang Town, Gaolin Village ; 21°37'48"N, 107°40'57"E; alt. 391 m; 17 April 2025; L. Bai & H. Y. Li BLSC-25041501 ( holotype: IBSC!) .

Diagnosis.

Indosasa fimbriligulata resembles I. glabrata but differs from the latter in having white strigose internodes when young, hollow internodes without pith or with a little clastic pith, abaxial surface of culm leaf sheaths scattered with tufted brown setae, well-developed culm leaf auricles, and culm leaf ligule apex with long fimbriae.

Description.

Rhizomes leptomorph. Culms diffuse, erect, sometimes flexuose, 2–4 m tall and 0.5–1.5 cm in diameter; internodes flattened on branching side, with two longitudinal ridges and three grooves above branching points along the branching side, 30–50 cm long, initially green to dark green, yellow-green when aged, white strigose when young, glabrescent when old, white powdery only at infranodal regions; walls 3–4 mm thick, cavity hollow without pith or with slightly clastic pith; supra-nodal ridges strongly raised, sheath scars prominent, with a corky ring and densely brown setose when young, glabrescent when old, with persistent remains of sheath base. Branch supra-nodal ridges strongly raised and asymmetrically swollen. Primary buds solitary, triangular, yellowish green, not sunken into culm, margin densely ciliate. Branch complement with three branches at each culm node. Culm leaf sheaths initially green with small purple dots, more so on the marginal part, turning to straw when old, tardily deciduous, narrow and long triangular, papery, abaxially scattered with tufted brown setae, densely brown setose at base, margins densely ciliate; auricles small, ovate to triangular, ca. 1 × 0.5 mm; oral setae well-developed, many, straight or slightly tortuous, 2–10 mm long; ligules arcuate, ca. 2 mm tall, abaxially puberulent, apex long fimbriate, fimbriae many, straight or slightly tortuous, 3–7 mm long; blades reflexed, linear to linear-lanceolate, 0.8–3 × 0.1–0.3 cm, 3 / 50–6 / 50 as long as sheath, apex acuminate, base narrowed, adaxially sparsely brown setae, abaxially glabrous. Foliage leaves 4–7 per ultimate branchlet; sheaths 3.5–6.5 cm long, glabrous, longitudinal ribs conspicuous when dry; auricles well-developed, ovate to triangular, 3–5 × 1–3 mm; oral setae many, straight or slightly tortuous, 3–20 mm long; ligules short, truncate, 0.5–1 mm tall, abaxially pubescent; blades lanceolate, papery, 9.5–24 × 1.5–3.8 cm, apex acuminate, base cuneate to widely cuneate, glabrous on both sides, one margin serrulate, other margin entire, secondary veins 5–8 pairs, transverse veinlets conspicuous. Inflorescence unknown.

Phenology.

New shoots from April to June.

Distribution and habitat.

This new species has been found only in its type locality so far. It usually occurs on mountain slopes near roadsides and streams.

Etymology.

The specific epithet refers to the fimbriate culm leaf ligule of this species, which is rarely seen in other Indosasa species. Its Chinese name is given as 流苏大节竹 [liú sū dà jié zhú].

Additional specimens examined.

China • Guangxi: Fangchenggang City, Naliang Town, Gaolin Village ; 21°37'34"N, 107°41'8''E; alt. 443 m; 15 June 2025; Z. Y. Niu, NZY 297 ( IBSC) .

Local usage.

Old culms are used for fences.

Figures

Figure 2. Indosasa fimbriligulata N. H. Xia, Z. Y. Niu & Y. H. Tong. A. Habit; B. Old culm; C. Culm bud; D. Branch complement with three branches at culm node; E. Portion of culm leaf showing leaf blade; F. Portion of culm leaf showing sheath base; G. Culm pith. Scale bars: 5 cm (G).

Figure 3. Indosasa fimbriligulata N. H. Xia, Z. Y. Niu & Y. H. Tong. A. Branch complement, showing strongly raised and asymmetrically swollen branch supra-nodal ridges; B. Foliage leafy branchlets; C. Ultimate foliage leafy branchlet; D. Portion of foliage leafy branchlet showing auricles and oral setae; E. Portion of culm leaf, showing culm leaf blade; F. Culm leaf ligule with long fimbriae; G. Culm leaf sheath base. Scale bars: 5 cm (A); 10 cm (C); 5 mm (F); 1 cm (D, E, G).

Figure 4. Indosasa fimbriligulata N. H. Xia, Z. Y. Niu & Y. H. Tong. A. Culm leaf sheath; B. Portion of culm, showing leaf blade, node, and internode; C. Culm node, showing culm bud and sheath scar; D. Branch complement with three branches at culm node, showing strongly raised and asymmetrically swollen branch supra-nodal ridges; E. Ultimate foliage leafy branchlet. Scale bars: 2 cm (A – E).