Corresponding author: Gang Hao (
Academic editor: W. A. Mustaqim
A new species,
Yan H-F, Li J-X, Liu T-J, Hao G (2023)
Some new
Historical taxonomic literature has been consulted (e.g.
China. Hunan Province, Yueyang City, Pingjiang County, Lutou Forest Farm,
Herbs perennial, 20 to 70 cm tall. Stems erect, later arched to reclined, simple or shortly branched, initially covered with rust-coloured multicellular hairs, glabrescent. Leaves opposite; petioles 0.6–1.1 cm long, sparsely strigillose; blades broadly ovate, 1.2–2.8 × 0.8–1.8 cm, sparsely strigillose abaxially, densely short black glandular striate, base broadly cuneate, margin subentire, apex subacute to obtuse; midrib sunken abaxially, prominent abaxially when dry, secondary veins 3 or 4 pairs, veinlets inconspicuous. Flowers solitary or paired, in axis of apical leaves; pedicel 1–1.8 cm, glandular pubescent. Calyx 5-parted, green, lobes lanceolate, 5–6 mm long, abaxially cristate; crest widest at base, ca. 2 mm, black glandular striate, apex acute. Corolla yellow, tube ca. 2 mm long, lobes elliptic-lanceolate, ca. 11 × 4 mm, densely black glandular striate, apex obtuse. Stamens 5, filaments 3.2–3.5 mm long, connate basally into a tube, tube part 3.8–4.0 mm long, adnate to corolla tube, anthers oblong, ca. 1.8 mm long, dorsifixed, opening by lateral slits. Ovary ovoid, 1 mm long, glabrous, style ca. 7 mm long, stigma capitate. Capsules subspherical, ca. 5 mm in diameter, glabrous.
The new species is currently known only from the type locality in Hunan Province, i.e. Lutou Forest Farm in Pingjiang County, Yueyang City. It grows at the edge of secondary mixed-evergreen forests, or under open forest on the hillside, at an altitude of ca. 400–450 m a.s.l.
Flowering from May to June, fruiting from July to August.
The new species is named in honour of Prof. Feng-Hwai Chen, a Chinese plant taxonomist and horticulturist, who devoted all his life to the development of botanical gardens in China and made considerable contributions to the study of
Simplified Chinese: 芦头过路黄; Chinese Pinyin: Lútou Guò Lù Huáng. “Lútou” means the flowers of
Based on our field investigations in Yueyang City and adjacent areas (e.g. Hubei and Guangxi Provinces) in the past ten years, only one population with ca. 1000 individuals of the new species has been found in an area of 10 km2 in Lutou Forest Farm, Pingjiang County, Yueyang City. Moreover, the habitats are under threat from road construction and timber harvesting. Therefore, the conservation status of the new species is assessed as Critically Endangered (
Based on the classification of
Holotype of
Living plant of
Main morphological differences between
Features |
|
|
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Lamina shape | broadly ovate, base rounded to truncate, apex subacute to obtuse | broadly ovate to suborbicular, base cordate, apex subacute to obtuse | broadly ovate to ovate, base rounded to truncate, apex acute to acuminate |
Lamina glands’ type | short striate | mix of both striate and punctate | punctate |
Arrangement of flowers | solitary or paired in axis of apical leaves | solitary, in axis of middle and upper leaves | solitary or paired, in axis of middle and upper leaves |
Calyx lobule spur | Absent | Present | absent |
Corolla lobule glands | densely striate | densely striate | punctate |
Whether the development of the crest to the calyx lobes, i.e. the winged keel of the calyx lobes, is a synapomorphy and those species constitute a monophyletic group in
The study was financially supported by the National Natural Science Foundation of China (grant nos. 32070220 and 31870192) and the Biological Resources Programme, Chinese Academy of Sciences (KFJ-BRP-017-104). We thank Yun-Xiao Liu for the line drawings of the holotype, and Quan-Ai Zou and Chun-Lai Zhang from Lutou Forest Farm for samples.