Phyllostachys viridivagina G. H. Lai & J. J. Yue, 2022

Lai, Guang-Hui & Yue, Jin-Jun, 2022, New taxa of the genus Phyllostachys (Poaceae: Bambusoideae) from east China, Phytotaxa 576 (2), pp. 193-202 : 194-195

Phyllostachys viridivagina G. H. Lai & J. J. Yue , sp. nov. (Figs. 1,2)

Type: — CHINA. Anhui Province: Guangde County, Taozhou Town, Hengshan National Forest Park , Changshanling , National Bamboo Germplasm Resource Bank , cultivated on a hill, elevation 78 m, 30°54’52.84’’N, 119°23’30.86’’E, 27 April 2015, G. H. Lai 15001 (holotype, AAUF!; isotypes, herbarium of Guangde Forestry Institute!) .

Diagnosis: —The new species is very particular in Phyllostachys sect. Phyllostachys , and is easily distinguished from the other species of this section by young culms without pruina, greenish, sparsely brown-spotted, and abaxially glabrous culm leaf sheaths without pruina and with obvious veins, and apically shortly white ciliate culm leaf ligules.At first glance, the new species is somewhat similar to P. elegans , P. dulcis or P. bambusoides , but differs in having shinygreen young culms without pruina, abaxially glabrous greenish culm leaf sheaths without pruina, apically truncate to arcuate culm leaf ligules, and abaxially glabrous foliage leaf blade (except puberulent base). A detailed comparison among them is provided in Table 1 .

Description:— Rhizomes monopodial, internodes without air canals in transverse section. Culms 4–6 m tall and 1.8–2.7 cm in diameter, straight and apically recurved, young ones shiny-green, glabrous, not pruinose; old ones green or gray-green, hardly covered with fuliginous powder; nodes moderately or strongly prominent, supranodal ridge more prominent than sheath scar; internodes 13–21 cm long; intranodes ca 2 cm long; branches 2 at each node, subhorizontal in the lower nodes. Culm leaves longer than internodes, sheaths thinly coriaceous, greenish when fresh, soon becoming pale yellow-green or yellowish slightly tinged with brown, initially pale green-purple and later becoming pale yellowbrown or desiccative toward margins and apex, sparsely brown spotted with spots usually scattered below middle part, but obscure or fewer on smaller sheaths, with obvious veins, abaxially glabrous and not pruinose; auricles well developed, initially greenish, later becoming yellow-green, falcate or shortly falcate, margin fringed with long crinkly setae initially tinged with greenish and later becoming purplish; ligules 2–2.5 mm tall, initially greenish, sometimes slightly purplish toward upper part and margin, apex truncate to arcuate, sometimes slightly oblique or slightly erose, sparsely white ciliolate (almost eciliate on the sheaths on lower part of culm); blades linear-lanceolate or linear, purplegreen, initially crinkled on upper part, later flat or wavy, reflexed. Leaves 3–5 per ultimate branchlet; foliage leaf sheath initially purplish, glabrous; auricles developed, pale yellow-green or tinged with purple on margin, margin fringed with radial purple setae; inner ligules tender-green and tinged with purple (obvious especially on margin), obviously exserted, 1–2 mm long, apex arcuate and very shortly white ciliate; blades linear-lanceolate, 8–14× 1.1–2 cm, adaxially green, abaxially nearly glaucous and white puberulent toward base, lateral nerves 5- or 6-paired, transverse veins obscure. Inflorescence unknown.

Distribution and habitat:— The new species is cultivated in National Bamboo Germplasm Bank, Changshanling, Hengshan National Forest Park, Taozhou Town, Guangde County, Anhui Province and Hengshanqiao Town, Wujin District, Changzhou City, Jiangsu Province. The population in Jiangsu covers an area of about 0.03 ha. at elevations of 35– 38 m.

Local use: —Its shoots taste delicious, and are used for fresh food or making dried shoots.

Etymology:— The specific epithet “ viridivagina ” refers to the shoots of the new species with green culm sheath, which is obviously different from those of the other species in Phyllostachys sect. Phyllostachys .

Phenology: —Shoot developed in mid to late April.

Chinese name:—Ḥạljẖ (pinyin: lǜ bŭ jî zhú).

Conservation status:—Only cultivated plants of the new species are found, and so far, no wild populations have been discovered from Anhui or Jiangsu. According to IUCN Red List Categories and Criteria (vers. 3.1 2nd ed.), it is therefore assigned a preliminary status of “Data Deficient” (DD).

Discussion:— Phyllostachys was divided into two sections, P. sect. Phyllostachys and P. sect. Heterocladae Wang & Ye (1980a: 16) based on vegetative and floral morphology (Wang et al. 1980, 1996; Wang & Stapleton 2006; Ma et al. 2014). P. sect. Phyllostachys is characterized by having rhizome internodes without air canals in transverse section, culm nodes with intranode 2–3 mm long, brown or dark brown spotted culm leaf sheaths, narrowly lanceolate to linear usually horizontal or reflexed culm leaf blades with base usually narrower than ligule, and spicate flowering branchlets, while P. sect. Heterocladae has rhizome internodes with a ring of air canals in transverse section, culm nodes with intranode ca. 5 mm long, usually unmarked culm leaf sheaths, triangular to triangular-lanceolate and usually erect appressed culm leaf blades with base as wide as ligule or nearly so, and capitate or subcapitate flowering branchlets. Although the floral morphology of this new species is still unknown so far, its vegetative characteristics, such as rhizome internodes without air canals in transverse section, culm nodes with intranode ca. 2 mm long, culm leaf sheaths tinged with brown spots, and reflexed and linear-lanceolate to linear blade with base obviously narrower than ligule, are rather consistent with those of P. sect. Phyllostachys . Thus, the new species should be placed in this section.

At first glance, Phyllostachys viridivagina is similar to P. elegans , and in some vegetative characters, it also somewhat closed to P. dulcis and P. bambusoides , but it is obviously different from the latter three species (see Table 1 ).