Research Article |
Corresponding author: Jin-Jun Yue ( yuejinjun@163.com ) Academic editor: Weilim Goh
© 2024 Dan-Dan Zhao, Jin-Jun Yue.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Zhao D-D, Yue J-J (2024) Chimonobambusa pleiacantha (Poaceae, Bambusoideae), a new species from southeast Sichuan, China. PhytoKeys 241: 229-239. https://doi.org/10.3897/phytokeys.241.120017
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Chimonobambusa pleiacantha, a newly-identified species of the genus Chimonobambusa Makino from southeast Sichuan, China, is meticulously described and illustrated herein. It is morphologically similar to Ch. tuberculata, but differs in having 4-angled internodes, thicker wall to 4.5–8.5 mm, more reclinate and elongated root thorns to 5–8 mm long, culm internodes with three grooves and two longitudinal ridges on the branch-bearing side, persistent culm leaves, densely brown-purple setose at the bottom of culm leaf sheaths together with sheath scar, developed foliage leaf fimbriae, 6–8 on each shoulder, ca. 3–8 mm long, abaxially white pubescent foliage leaf blades. Phenologically, new shoots usually appear in September to October. In the light of these key morphological and phenological characteristics, Ch. pleiacantha was identified as a new species of the genus Ch. Makino which is different from published species of this genus.
Bambuseae, Chimonobambusa, new species, taxonomy
Chimonobambusa Makino, as a quite valuable genus in Bambusoideae, has garnered considerable attention. The yield of the plants is relatively high and the bamboo shoots have a high nutritional value. Usually, the bamboo shoots taste delicious and can be used for making a variety of cuisines. Furthermore, several species offer substantial economic benefits, notably due to the off-season development of new shoots in autumn, which presents a distinct seasonal advantage over other bamboos prevalent in the market. In recent years, in order to deeply implement the principles of the seed industry, enhance the collection, preservation, organisation and identification of bamboo germplasm resources and strengthen the foundation of breeding, many botanists have been continuously investigating the resources of the genus Chimonobambusa. In the process, some new taxa have been discovered.
Chimonobambusa Makino is characterised by rhizomes amphipodial, internodes terete or 4-angled, basal nodes often with a ring of sparse or dense root thorns, culm leaf auricles minute or absent, culm leaf blade reduced to 1 cm, narrow and inflorescence fully bracteate, 1–3 single pseudospikelet racemes loosely fasciculate, subtended by gradually enlarged bracts, spikelets sessile, rachilla disarticulating, glumes usually 1–3, frequently one subtending a bud, lodicules 3, membranous, stamens 3, filaments free, ovary ellipsoid, style 1, stigmas 2 or 3, plumose. It is mainly distributed in the south-western mountainous regions of China with its core distribution spanning Yunnan, Guizhou and Sichuan Provinces and a few species of the genus extend to the southern slopes of the Qinling Mountains or along the south-eastern coast. The optimal elevation range for their growth is from 500 to 2600 m (
Xingwen County is located in the south-eastern zone of Yibin City, Sichuan Province and is characterised by its distinctive climate, topography, hydrology and soil conditions, which have fostered the development of numerous high-quality bamboo species of the genus (
The plant material of the new species was collected from Jiusi Township, Xingwen County, Sichuan Province, on 14 October 2023. Morphological features were observed and documented during the field survey. The height of the plant was measured using a hand-held laser rangefinder, while other significant quantitative traits for taxonomic classification, such as bamboo diameter, internode length, leaf length and leaf width, were measured using a tape measure and Vernier caliper. The specimens were stored in the Herbarium of Anji Bamboo Exposition Garden, Zhejiang, China and Research Institute of Subtropical Forestry, Chinese Academy of Forestry. Terminologies in this paper referring to the relevant descriptions follow
Chimonobambusa pleiacantha resembles Ch. tuberculata, but can be effortlessly distinguished by having 4-angled internodes (vs. terete), thicker wall to 4.5–8.5 mm (vs. 2–3 mm), more reclinate and elongated root thorns to 5–8 mm (vs. 2–4 mm), culm internodes with 3 grooves and 2 longitudinal ridges (vs. grooves obscure), persistent culm leaves (vs. deciduous), densely brown-purple setose at the base of culm leaf sheaths together with sheath scar (vs. without dense setae), conspicuously developed and persistent foliage leaf fimbriae to ca. 3–8 mm long (vs. spare and caducous) and foliage leaf blades with white pubescence on the abaxial side (vs. abaxially glabrous). (Table
Characters | Ch. pleiacantha | Ch. tuberculata |
---|---|---|
Culm height | 2–7 m | 3–4 m |
Culm diameter | 0.5–4 cm | 1.2 cm |
Culm internode | internodes 4-angled, 10–20 cm long, flattened on branch-bearing side, with 3 grooves and 2 longitudinal ridges; wall 4.5–8.5 mm | internodes terete, 14–18 cm long, grooves indistinct on branch-bearing side; wall 2–3 mm |
Culm intranode | nodes below mid-culm each with a ring of 4–10 root thorns, root thorns usually slanted downwards and curved at the apex, 5–8 mm long | nodes below mid-culm each with a ring of 4–12 straight root thorns, 2–4 mm long |
Culm leaf | persistent | deciduous |
Culm leaf sheath | initially yellowish tuberculate setose and densely brown-purple setose at the base together with sheath scar | initially yellowish-brown adnate setose |
Foliage leaf fimbriae | 6–8 on each shoulder, ca. 3–8 mm long, straight | sparse and caducous |
Foliage leaf auricle | present or absent | absent |
Foliage leaf blade | oblong lanceolate, 10–30 cm × 1.5–3 cm, abaxially white pubescent, secondary veins 5–7-paired, transverse veins indistinct | lanceolate, 19–25 cm × 2–3 cm, abaxially glabrous, secondary veins 6–9-paired, transverse veins distinct |
New shoot | September to October | August to September |
Habitat and distribution | on the hillside or under the forest at altitudes of 1000–1500 m, Xingwen County, southeast Sichuan | on the hillside at the elevation of 1300–1450 m, Yongshan County, Yunnan |
China. Sichuan: Xingwen County, Jiusi Township, Fangbei Village. 28°6′19″N, 105°2′25″E, 1344 m alt., 16 October 2023, D. D. Zhao & J. J. Yue 23101 (holotype: Herbarium of Anji Bamboo Exposition Garden!; isotypes: Herbarium of Research Institute of Subtropical Forestry, Chinese Academy of Forestry!).
Shrubby bamboo. Rhizomes amphipodial. Culms 2–7 m tall, 0.5–4 cm in diam., erect; internodes 4-angled, 10–20 cm long, flattened on branch-bearing side, with 3 grooves and 2 longitudinal ridges; wall 4.5–8.5 mm. Intranodes 1–2 mm long, nodes below mid-culm each usually with a ring of 4–10 root thorns, root thorns usually slanted downwards and curved at the apex, rarely horizontally arranged, 5–8 mm long. Branches usually 3 per node, sometimes 4–5 on upper nodes. Young culms green, initially white pubescent and tuberculate hispid, later verrucose, rough; old culms dark green. Sheath scar initially with a densely upward brown-purple setose ring. Culm leaves shorter or longer than internodes, persistent; sheaths thinly papery or papery, yellowish-white when fresh and tinged with purplish-red towards apex, abaxially initially yellowish tuberculate setose and densely brown-purple setose at the base together with sheath scar, margins faint yellow ciliate; transverse veins indistinct; auricles and ligule both absent; fimbriae absent; blade erect, 0.5–1mm long. Foliage leaves 3–5 per ultimate branch; sheaths abaxially glabrous, upper margins ciliate; fimbriae developed, neatly arranged, 6–8 on each shoulder, straight, ca. 3–8 mm long; auricles present or absent; ligule ca. 0.5 mm; petiole 2–3 mm long; blades oblong lanceolate, 10–30 cm × 1.5–3 cm, abaxially greyish-green and white pubescent, secondary veins 5–7-paired, transverse veins indistinct, margins serrulate. New shoots from September to October are prone to browning after harvesting. Inflorescence unknown.
毛刺竹(Chinese name), máo cì zhú (Chinese Pinyin); 刺竹(Local common name), cì zhú (Chinese Pinyin).
Chimonobambusa pleiacantha grows under mixed forests in the south-western mountainous area of Xingwen County with quite a number of populations involving large areas of both wild and cultivated groups. Additionally, the local government attaches great importance to the scientific development of bamboo resources, so it can be effectively protected. Thus, we tentatively assessed it as “Least Concern” (IUCN 2022).
Ch. pleiacantha A–C shoots, showing fresh culm leaf sheaths yellowish-white, apically purplish-red D the abaxial side of culm leaf sheath, with yellowish tuberculate setae E the lateral side of culm leaf sheath, showing margins with faint yellow cilia F the base of culm leaf sheath, with densely brown-purple setae G upper part of culm leaf in adaxial view, showing absent ligule and auricles H upper part of culm leaf in abaxial view, showing shorter blade.
Bamboo shoots developed in September and October.
Chimonobambusa Makino was first published as a new genus by Makino from Japan in 1914, which involved two species, Ch. quadrangularis (Fenzi) Makino and Ch. marmorea (Mitford) Makino; meanwhile, the flowers of Ch. marmorea (Mitford) Makino were described and selected as the type species of Chimonobambusa (
By reviewing the original published literature and investigating the origins of the genus Chimonobambusa, we discovered that Ch. pleiacantha is similar to Ch. tuberculata, but exhibits distinct differences in several aspects. During the investigation, we found that the information of the collection site of the type specimen of Ch. tuberculata was incorrectly documented, the correct location is “Shuidong Zi(水洞子), Xisha Township, Yongshan County, Yunnan Province” not “Xiaodong Zi(小洞子), Xisha Township, Yongshan County, Yunnan Province”. Furthermore, the morphological characteristics of Ch. tuberculata are described as “internodes terete, grooves indistinct on branch-bearing side; young culms initially with brown dense tuberculate hispid, later rough after verrucae falling; nodes below mid-culm each with a ring of 4–12 root thorns; culm leaves deciduous, papery or thickly papery, abaxially initially with yellowish setose, becoming black verrucose; 3 or 4 leaves per ultimate branch; blade lanceolate, 19–25 × 2.2–3 cm, secondary veins 6–9-paired, transverse veins distinct. Inflorescence unknown. New shoots Aug-Sep (
This study was supported by the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding (2021C02070-4). We are thankful to Mr. Yong-Chao Zhou of Forestry and Bamboo Industry Development Service Center of Xingwen County for his support during the field survey. We are thankful to Mr. Guang-Hui Lai of Forestry Development Service Center of Guangde County for his support during the Ch. tuberculata field survey.
The authors have declared that no competing interests exist.
No ethical statement was reported.
This study was supported by the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding (2021C02070-4).
Investigation: JJY, DDZ. Writing-original draft: DDZ. Writing-review and editing: JJY.
Dan-Dan Zhao https://orcid.org/0009-0005-5155-7006
Jin-Jun Yue https://orcid.org/0000-0001-9606-6394
All of the data that support the findings of this study are available in the main text.