Research Article |
Corresponding author: Yi-Hua Tong ( yh-tong@scbg.ac.cn ) Academic editor: Bing Liu
© 2023 Yong-Jie Guo, Ting Zhang, Ji-Dong Ya, Wei Zhang, Xiu-Ying Shen, Zhou-Dong Han, Jing-Bo Ni, Jian-Yong Su, Yi-Hua Tong.
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:
Guo Y-J, Zhang T, Ya J-D, Zhang W, Shen X-Y, Han Z-D, Ni J-B, Su J-Y, Tong Y-H (2023) Vaccinium usneoides (Ericaceae), a new species from Yunnan, China. PhytoKeys 236: 187-195. https://doi.org/10.3897/phytokeys.236.112658
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Vaccinium usneoides (Ericaceae), a new species from Fugong County of Yunnan Province, China is described and illustrated. This new species belongs to Vaccinium sect. Calcicolus and is most similar to V. brachyandrum, but differs in its branches hanging down, much smaller leaf blades, shorter inflorescences and pedicels, non-glandular tomentellate or densely pubescent inflorescence rachis and pedicels, densely white-pubescent hypanthium and pilose filaments.
Gaoligong Mountain, morphology, Vaccinieae, Vaccinium arbutoides
The genus Vaccinium L. (Ericaceae), with about 450–500 species distributed worldwide, is the largest genus of the blueberry tribe (
During several field trips to Gaoligong Mountain, we encountered an interesting Vaccinium species. This species is epiphytic on large trees with long hanging-down branches, which looks just like beard lichens from a distance. The inflorescence of this species is very hairy and shorter than and shaded by leaf blades, suggesting a close relationship with V. brachyandrum C. Y. Wu & R. C. Fang, another sympatrically distributed species in Gaoligong Mountain. However, V. brachyandrum owns scrambling branches and much larger leaf blades, which are totally different from this unknown species. After a careful comparison of morphology with similar congeneric species from China and adjacent Myanmar (
Flowering and fruiting materials were collected from Gaoligong Mountain during three field trips in May 2022, October 2022 and March 2023. Descriptions were based on both living and dried collections. The voucher specimens were deposited at the Herbaria of Kunming Institute of Botany, Chinese Academy of Sciences (
China. Yunnan Province: Fugong County, Shiyueliang Xiang, Yaduo Village, Nihajiadi (also called “Shibagongli” unofficially), Gaoligong Mountain, epiphytic on trees in evergreen and deciduous broad-leaved mixed forest, 27°9′55.0″N, 98°46′44.2″E, 2497 m a.s.l., 27 May 2022 (fl.), Ting Zhang, Ji-Dong Ya & Wei Zhang 22CS21979 (holotype:
This new species is close to V. brachyandrum in the short and hairy inflorescences (less than 3.5 cm) with many flowers and the abaxially glandular leaf blades with one basal gland per side and a caudate-acuminate apex, but can be immediately distinguished by its hanging-down (vs. scrambling) branches, much smaller leaf blades (2.5–5.5 × 0.9–1.8 cm vs. 8.5–11 × 4–6 cm) with fewer pairs of secondary veins (3–4 vs. 6–7), shorter inflorescence (1–1.5 cm vs. 1.5–3.5 cm), non-glandular tomentellate or densely pubescent (vs. glandular pubescent) inflorescence rachis and pedicel, shorter pedicel (0.7–1 mm vs. ca. 2 mm), densely white-pubescent (vs. glabrous) hypanthium and pilose (vs. glabrous) filament. A detailed morphological comparison between the two species is presented in Table
Vaccinium usneoides sp. nov. A habitat, the red ovals indicating this species B habit C leafy branches, the arrow showing the indumentum on young branchlets and leaf blades D flowering branchlets with young inflorescences E flowering branchlet F fruiting branchlet. A, B taken by Yi-Hua Tong C, F taken by Yong-jie Guo D taken by Ji-Dong Ya E taken by Ting Zhang.
A morphological comparison of Vaccinium usneoides and V. brachyandrum. The character information of the latter species is taken from
Characters | V. usneoides | V. brachyandrum |
---|---|---|
Branches | Hanging down | Scrambling |
Leaf blade | 2.5–5.5 × 0.9–1.8 cm | 8.5–11 × 4–6 cm |
Pairs of secondary veins | 3–4 | 6–7 |
Inflorescence length | 1–1.5 cm | 1.5–3.5 cm |
Indumentum on inflorescence and pedicel | Non-glandular tomentellate or densely pubescent | Glandular pubescent |
Hypanthium | Densely white-pubescent | Glabrous |
Pedicel length | 0.7–1 mm | ca. 2 mm |
Filament | Pilose | Glabrous |
Evergreen shrubs, epiphytic on tree trunks, sparsely branched; roots creeping firmly on tree trunks or branches; stems 0.5–3 m long, without swollen basal tuber or root swellings. Branches hanging down, young shoots brownish or greenish, terete or slightly angled, without lenticels, densely pubescent; old ones more or less glabrescent, brownish or greyish, often obviously angled in sicco. Perennating buds dimorphic (floral perennating buds at least twice the size of vegetative perennating buds). Leaves alternate; petiole short, curved, 2–5 mm long, 1–1.5 mm wide, densely pubescent, glabrescent when mature; blade narrowly ovate to oblong, 2.5–5.5 (including caudate apex) × 0.9–1.8 cm, thickly leathery, adaxially more or less transversely wrinkled when dry, especially for young ones, abaxially with evenly distributed and caducous appressed black glandular trichomes, trichome base papillate, both sides pubescent when young, glabrous when mature, base rounded to broadly cuneate, with 1 basal gland per side at ca. 1 mm distance from the junction of leaf blade base and petiole, margin entire, revolute, with a ca. 0.5 mm broad, cartilaginous edge, apex caudate-acuminate; veins impressed adaxially, more so when dry, obscure abaxially, secondary veins 3–4 per side, tertiary veins slightly prominent. Inflorescence short racemose, 1–1.5 cm long, axillary on biennial branches, shorter than and shaded by leaf blades, 8–14-flowered. Peduncle very short, inflorescence rachis 0.7–1 cm long, white-tomentellate or densely white-pubescent; bracts red on exposed part, greenish on covered part, broadly obovate, cucullate, 5–6 × 6–7 mm, abaxially more or less white-pubescent on mid-vein, more so on lower half, adaxially glabrous, margin ciliate, caducous; bracteoles 2, inserted at base of pedicel, greenish, sometimes tinged with red, obovate, 3.5–4 × 2–2.5 mm, indumentum similar to bracts, caducous. Pedicels greenish, very short, 0.5–1 mm long, densely white-pubescent, articulate with the hypanthium. Hypanthium greenish, obconical, 1–1.5 × 1–1.5 mm, densely white-pubescent, more so at base; calyx limb lobed nearly to base, lobes 5, green, more or less tinged with red, triangular, ca. 2 × 1.5 mm, abaxially white-pubescent at apex, otherwise glabrous, adaxially glabrous, apex acuminate, margin ciliate. Corolla red, urceolate-campanulate, slightly angled when young, 3.5–4 × ca. 3 mm, tube glabrous on both sides; lobes 5, ovate-triangular, reflexed, ca. 0.8 × 1 mm, abaxially white-pubescent at apex, otherwise glabrous, adaxially papillose, apex acuminate. Stamens 10, 2.8–3 mm long; filaments flat, slightly S-shaped, 1–1.2 mm long, papillose on both sides, margin pilose; anthers 1.8–2 mm long, thecae slightly longer than or nearly as equal as tubules; spurs 2, borne at abaxial base of tubules, 0.7–0.8 mm long, spreading. Disc yellowish-green, annular, glabrous; style cylindrical, slightly angled in sicco, 2.7–3 mm long, glabrous, stigma truncate; ovary pseudo-10-locular, each locule with several ovules. Fruiting pedicels 1–3.5 mm long; berries pale green to green when young, yellowish-green to purplish-red or dark purple when mature, globose, 4.5–6 mm in diam., densely white-pubescent, with persistent calyx lobes appressed at apex, ripe berries a little bitter. Seeds ovoid, 0.7–0.8 × 0.5–0.7 mm, testa brownish, reticulate.
Vaccinium usneoides sp. nov. A flowering branchlet B trichomes on abaxial surface of leaf blades C fruiting branchlet D flower E flower with corolla and calyx limb removed, showing androecium and gynoecium F stamens, adaxial (left), abaxial (middle) and lateral (right) view G seeds. Illustrated by Ding-Han Cui.
The species epithet is derived from the genus of beard lichen “Usnea” and the suffix “-oides”, which means the habit of this new species looks very much like beard lichen on trees from a distance. Chinese name is given as松萝越橘 (Pinyin: sōng luó yuè jú).
This species is currently known only from the type locality, i.e. the part of the Gaoligong Mountain in Fugong County. It grows on trees in mountainous evergreen and deciduous broad-leaved mixed forests at elevations of 2400–2800 m a.s.l.
Vaccinium usneoides is not rare in the type locality and the whole distribution area is under the protection of Gaoligongshan National Nature Reserve. Thus, the threat risk seems to be low. Since the type locality is very near the border of China and Myanmar, this species is probably also distributed in the adjacent area of Myanmar. Thus, it is best to assign a status of ‘Data Deficient’ (DD) for this species following the IUCN Red List Categories and Criteria (
Flowering in May–June and fruiting in October–November.
Vaccinium usneoides (paratypes): the same locality with holotype: 27°9′57.78″N, 98°46′14.91″E, 2661 m a.s.l., 27 October 2022 (fr.), Yong-Jie Guo, Zhou-Dong Han & Xiu-Ying Shen 22CS22598 (
China. Yunnan Province: Tengchong, Houqiao, 2720 m a.s.l., 18 May 1964, Su Kung Wu 6629 (holotype KUN1209465, isotype KUN1209466); ibid., 25°24′16.700″N, 98°8′43.869″E, 2564 m a.s.l., 22 August 2022, Yong-Jie Guo & Zhong-Lan Yang 22CS22523 (
In the key to Vaccinium in “Flora of China” (
According to Vander Kloet and Dickinson’s infrageneric classification of Vaccinium, V. usneoides fits well with the circumscription of V. sect. Calcicolus Kloet, which is characterised by an evergreen habit, dimorphic perennating buds (i.e. floral perennating buds at least twice the size of vegetative perennating buds), racemose inflorescences with large caducous bracts, pseudo-10-locular ovary, berry with 2–5 seeds per locule and soft seed testa (
We thank Chang-Hong Li and Zhong-Lan Yang from the Germplasm Bank of Wild Species, Kunming Institute of Botany, Chinese Academy of Sciences, Jie Yang from Fugong Forestry and Grassland Administration and YHT’s friends Bing-Mou Wang and Wei-Hao Pan for their help during field trips. Our thanks also go to the curators of
The authors have declared that no competing interests exist.
No ethical statement was reported.
This study was funded by Science and Technology Basic Resources Investigation Program of China (Grant No. 2021FY100200), National Wild Plant Germplasm Resource Center, Key-Area Research and Development Program of Guangdong Province (Grant No. 2022B1111230001) and the National Natural Science Foundation of China (Grant No. 31870180).
YJG: Investigation; Writing manuscript. TZ: Investigation; Funding acquisition. JDY, WZ, XYS, ZDH, JBN, JYS: Investigation. YHT: Investigation; Writing manuscript; Supervision; Funding acquisition.
Yong-Jie Guo https://orcid.org/0000-0003-1752-4495
Ting Zhang https://orcid.org/0000-0003-0939-8468
Ji-Dong Ya https://orcid.org/0000-0003-3389-1412
Wei Zhang https://orcid.org/0009-0003-5327-8698
Zhou-Dong Han https://orcid.org/0009-0001-9431-1349
Yi-Hua Tong https://orcid.org/0000-0002-5034-005X
All of the data that support the findings of this study are available in the main text.