Chimonobambusa farcta G.H.Lai & J.J.Yue, 2024

Lai, Guang-Hui & Yue, Jin-Jun, 2024, Chimonobambusa farcta (Poaceae, Bambusoideae), a new species from western Guangxi, China with taxonomic notes on C. pubescens and C. luzhiensis, PhytoKeys 239, pp. 13-27 : 13

Chimonobambusa farcta G.H.Lai & J.J.Yue sp. nov.

Figs 1 , 2 , 3

Diagnosis.

Chimonobambusa farcta with solid internodes of culms is similar to C. pubescens , but differs in having taller culm to 7 m (vs. 2.1 m) with longer internodes to 23.5 cm (vs. 14 cm) and intranodes to 4 mm (vs. 2 mm), intranode usually with a ring of 7-9 root thorns below mid-culm, abaxially brown or brown-purple verrucose-setose culm leaf sheaths with indistinct transverse veins, conspicuously developed culm leaf blade to 32 mm (vs. ca. 2 mm)long, longer foliage leaf sheaths to 5.2 cm (vs. 2.8 cm), larger and broader foliage leaf blade to 22 × 1.4 (vs. 12 × 0.9 cm) cm. It also somewhat resembles C. convoluta , but can be easily distinguished by having culm with solid internodes and longer intranode 2-4 mm (vs. 1-2 mm), very prominent nodes with supranodal ridge obviously more elevated than sheath scar, usually persistent and sometimes brownish striate culm leaf sheaths, longer culm leaf blade to 32 mm (vs. 20 mm), and abaxially glabrous foliage leaf sheaths (Table 1 ).

Type.

China. Guangxi: Lingyun County, Sicheng Town, Jinbao Village , Dashipo , 24°25'22"N, 106°30'29"E, 1261 m alt., 5 November 2022, G. H. Lai & J. J. Yue 22111 (holotype: AAUF!; isotypes: herbarium of Guangde Forestry Institute! and herbarium of Research Institute of Subtropical Forestry , Chinese Academy of Forestry !) .

Description.

Shrubby bamboo. Rhizome amphipodial. Culms 3-7 m tall, 0.5-1.5 cm in diameter, erect, straight or sometimes middle and lower part of culm slightly zigzag and more or less oblique at nodes; internodes 12-23.5 cm long, cylindrical, basically weakly flattened on branch-bearing side, hard, solid (rarely subsolid on upper culm), dark green (rarely purple striate) and not pruinose when young, with white or pale brown curved verrucae (more on bare part) and white short retrorse hairs arranged in longitudinal rows, green or brown when old, scarred and rough after verrucae falling, glabrescent, obviously dirty-powdery; intranode 2-4 mm long, usually with a ring of 7-9 hard root thorns below mid-culm; thorns top-shaped or conical, 2-5 mm long, horizontally spreading or slanted downward; supranodal ridge very prominent, sometimes geniculate-swollen on bud-bearing opposite side, obviously more elevated than sheath scar; sheath scars prominent, densely persistently brown setoses; buds 3 at each node, adnate, narrowly ovate or conical, middle one longer, prophyll ovate or broadly ovate, abaxially glabrous, margin brownish ciliate; branches initially 3 per node, later to more than 10 on upper nodes of culm, spreading. Culm leaves usually persistent, rarely late deciduous, obviously shorter than internodes (1/2-2/3 as long as them) on lower culm, subequal in length to, or longer than internodes on middle and upper culm; sheaths papery, variable in color, initially brownish, yellowish-green, yellowish-brown or purplish-brown, tinged with green and brownish-red toward convex apex, soon straw-colored, with small and dense purple-brown spots, sometimes brownish stirate, abaxially sparsely uniformly upward appressed brown or brown-purple verrucose-setose, long brown hispid near base, densely brown bristly at bottom together with sheath scar, marginally densely brown ciliate, obviously longitudinally ribbed, indistinctly transversely veined; auricles absent, fimbriae not developed, sometimes 1or 2 on each shoulder, suberect; ligule shorter than 1 mm, purple-brown, truncate or slightly arched, margin extremely shortly ciliolate or subglabrous; blade narrowly triangular, subulate or narrowly linear-lanceolate, initially green or brownish-green, tinged with yellow toward apex, 4-32 × 1.5-2.5 mm, erect, not articulate with sheath. Foliage leaves (2-)3-6(-9) per ultimate branchlet; sheaths 2.8-5.2 cm long, abaxially glabrous, margins white or yellowish ciliolate sometimes hardly ciliate; auricles inconspicuous, fimbriae developed, 5-10(-12) on each shoulder, 3-8 mm long, grey-white, neatly arranged, straightly extended, easily deciduous or broken; ligule not exserted, shorter than 1 mm, truncate, apex hardly or very shortly ciliolate; petiole 1-2 mm long, glabrous; blade linear-lanceolate, 9-22 × 0.7-1.4 cm, adaxially green and glabrous, abaxially greenish and white pubescent, secondary veins 3-6(-7)-paired, transverse veins distinct, apex long acuminate, base cuneate, one margin minutely serrulate-scabrid. Inflorescence and caryopsis unknown.

Vernacular names.

凌云寒竹 (Chinese name), líng yún hán zhú (Chinese Pinyin); 实竹 (Local common name), shí zhú (Chinese Pinyin).

Distribution and habitat.

Chimonobambusa farcta was only found from Lingyun County, between Mt. Qinglong and Mt. Donglan, western Guangxi, China. It grows under the evergreen broadleaved forest of steep hillsides at an altitude of 1200-1500 m (Figs 3 , 4 ).

Conservation status.

This new species has been commonly found in the northwestern mountainous area of Lingyun County with quite a few populations, where its area of occupancy is less than 50 km2. Fortunately, its current distribution area happens to be included in the Sishuihe Nature Reserve and is under effective protection. Thus, it is assigned the status of "Least Concern" (LC) according to the IUCN Red List Categories and Criteria ( IUCN Standards and Petitions Committee 2022).

Phenology.

New shoots developed in October.

Etymology.

The specific epithet " farcta " refers to the culms of the new species with solid internodes.

Additional specimens examined (paratypes).

China. Guangxi: Lingyun County, Sicheng Town, Jinbao Village , Dashipo , 24°25'52"N, 106°30'30"E, 1294 m alt., 5 November 2022, J. X. Ma & D. D. Zhao 22001 (Anji Bamboo Exposition Garden); same locality, 24 May 2023, G. H. Lai & J. J. Yue 23030 (herbarium of Guangde Forestry Institute); Lingyun County , Sicheng Town , Jinbao Village , Bajiaoshan, 24°24'51"N, 106°30'17"E, 1316 m alt., 22 October 2023, G. H. Lai & J. J. Yue 23042 (herbarium of Guangde Forestry Institute) .

Figures

Figure 1. Chimonobambusa farcta A upper part of shoot B culm leaf in abaxial view, showing sparse verrucose setae; culm leaf in adaxial view, showing slightly arched ligule and narrowly linear-lanceolate blade C part of culm, showing conical root thorns and narrowly ovate buds at node, and solid internode D base of culm leaf sheath and upper part of an internode of young culm, showing indumentum and curved verrucae E a node of mid-culm, showing branch complement F mouth of foliage leaf sheaths, showing developed fimbriae G branchlets and ultimate branchlets, showing foliage leaf complement. Illustrated by Sai-Jun Ma based on G. H. Lai & J. J. Yue 22111.

Figure 2. Chimonobambusa farcta A clump B rhizome C a node in lower culm, showing bud complement D intranodes of lower culms, showing an arrangement of conical or top-shaped, hard root thorns E, F cross section of old and young culms, showing solid internode G part of culm internode, showing dense curved verrucae H upper part of an internode of young culm, showing short, retrorse hairs arranged in longitudinal rows I, J node of mid-culm or upper culm, showing branch complement K branchlet and foliage leaves in adaxial view, showing sheaths, fimbriae, and blades L base of foliage leaves in abaxial view M part of foliage leaves in abaxial view, showing pubescent abaxial surface. Photos by Guang-Hui Lai.

Figure 3. Chimonobambusa farcta A, B, C shoots, showing variable colors on sheaths D upper part of shoot, showing a few fimbriae and nearly erect blade E, F culm leaf sheath in abaxial view, with small purple-brown spots and sparse verrucose setae, sometimes with brownish stripes G culm leaf sheath in lateral view, showing densely brown ciliate margins H base of culm leaf sheath, showing indumentum I upper part of culm leaf in abaxial view, showing arched top of sheath J upper part of culm leaf in abaxial view, showing truncate short ligule and blade K upper part of culm leaf in adaxial view, showing slightly arched short ligule. Photos by Guang-Hui Lai.

Figure 4. The habitat and geographical distribution of Chimonobambusa farcta A clump growing in natural habitat B the red pentagon showing its distribution area. Photo A by Guang-Hui Lai.