Research Article |
Corresponding author: Xiaoguo Xiang ( xiangxg2010@163.com ) Academic editor: Alan Paton
© 2019 Zhaowen Wu, Zhiyou Guo, Chaoyi Deng, Zhenyu Li, Xiaoguo Xiang.
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:
Wu Z, Guo Z, Deng C, Li Z, Xiang X (2019) Hemiboea albiflora, a new species of Gesneriaceae from Guizhou, China. PhytoKeys 122: 79-86. https://doi.org/10.3897/phytokeys.122.33783
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Hemiboea albiflora X.G.Xiang, Z.Y.Guo & Z.W.Wu, sp. nov., a new species of Gesneriaceae from Guizhou, China, is described and illustrated. This species was previously listed informally as a variety of H. gamosepala, but it differs significantly from H. gamosepala by its 5-parted calyx from the base, longer peduncle, white corolla and longer pistil. Based on recent extensive observations, this new species is similar to H. cavaleriei var. paucinervis and H. subcapitata but differs from them by its longer petiole, larger involucre, white corolla and longer staminal filaments. The conservation status of this species is considered to be “Vulnerable” (VU) according to the IUCN Red List Categories and Criteria.
Hemiboea, Gesneriaceae, limestone flora, new species
Hemiboea C.B. Clarke is a medium-sized genus of Gesneriaceae distributed in central to southern China, northern Vietnam and Southern Japan (
During our expedition to Xingyi City, Guizhou Province, China in 2017, we collected two populations of Hemiboea gamosepala var. albiflora C. Y. Deng & M. T. An, nom. nud. invalidly published in
Morphological observations and measurements of the new species were carried out, based on living plants and dry specimens (PE, QNUN and XIN). The photographs were taken in the field. All morphological characters were studied under dissecting microscopes and are described using the terminology presented by
China. Guizhou: Xingyi City, Maling River Valley, 26°8.47'N, 104°57.27'E, altitude 967 m, on rock faces near the river, 12 October 2017, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017061 (holotype: PE!; isotypes: PE!, QNUN!).
H. albiflora differs significantly from H. gamosepala by its 5-parted calyx from the base (vs. 5-lobed from middle), longer peduncle, 3–6 cm (vs. 0.2–0.4 cm), white corolla (vs. pink corolla) and longer pistil, 2–2.5 cm (vs. ~ 1.5 cm). After extensive observations, Hemiboea albiflora is close to H. cavaleriei var. paucinervis W. T. Wang et Z. Y. Li and H. subcapitata C.B. Clarke, but differs from them through its longer petiole, 3–6 cm; larger involucre, 2–3 cm in diameter; white corolla, glabrous outside; and longer staminal filaments, 1.8–2 cm long. The detailed morphological comparisons are listed in Table
Morphological comparisons between H. albiflora and the similar species H. gamosepala, H. cavaleriei var. paucinervis and H. subcapitata.
H. albiflora | H. gamosepala | H. cavaleriei var. paucinervis | H. subcapitata | |
---|---|---|---|---|
Leaf | ||||
Petiole | 3–6 cm | 0.6–6 cm | 0.5–6.5 cm | 0.5–5.5 cm |
adaxial surface | green, sparsely pubescent | deep green, glabrous | green, glabrous | deep green, glabrous or sparsely pubescent |
abaxial surface | pale green, glabrous | pale green or pale purple, glabrous | pale green or purple, glabrous | pale green, glabrous or sparsely pubescent |
Veins on each side of midrib | 5–9 | 4–10 | 4–8(-9) | 5–6 |
Flower | ||||
Peduncle | 2–3 cm long | 0.2–0.4 cm long | 0.5–6.5 cm long | 2–4(-13) cm long |
Involucre | 2–3 cm in diameter | 1.8–2.3 cm in diameter | 1–2.5 cm in diameter | 1.5–2.2 cm in diameter |
Corolla | 4–5.5 cm long, outside white, glabrous | 3.8–4 cm long; outside pink, sparsely glandular-puberulent | 3.0–4.8 cm long, outside white, pale yellow or pink, sparsely glandular-puberulent | 3.5–4.2 cm long, outside white, sparsely glandular-puberulent |
Tube | 3.5–4.5 cm long | 3–3.1 cm long | 2.3–3.3 cm long | 2.8–3.5 cm long |
Filaments | 1.8–2 cm long | 1.2–1.5 cm long | 1.0–1.3 cm long | 0.8–1.3 cm long |
Anther | ovate-elliptic, 2–3 mm long | subovate, ca. 3 mm long | elliptic, 3–3.2 mm long | elliptic, 3–4 mm long |
Staminodes | 2 | 2 | 2 | 3 |
Pistil | 2–2.5 cm long | ca. 1.5 cm long | 1.7–2.5cm long | 3.2–3.5 cm long |
Capsule | 2–3 cm long | 1.8–2.4 cm long | 1.5–2.5 cm long | 1.5–2.2 cm long |
Perennial herbs. Stems ascending, subterete, 40–100 cm tall, 2–5 mm in diameter, simple, sparsely purple-spotted, glabrous, juicy when fresh, nodes 5–10, not swollen. Leaves opposite, herbaceous; petiole 3–6 cm long, about 2 mm in diameter, almost terete, adaxially valleculate, margin erect and rounded, glabrous, green; leave blade oblong-lanceolate or ovate-lanceolate, 7–15 cm long, 3–5.5 cm wide, apex acuminate, rarely acute, margin repand-crenate, base usually oblique, adaxial surface green, sparsely pubescent, abaxial surface pale green, glabrous; lateral veins 5–9 on each side of midrib. Cymes subterminal, sometimes axillary, 4–8-flowered; peduncle 2–3 cm long, 3–4 mm in diameter glabrous, sparsely purple-spotted; involucre subglobose or broad ovoid, 2–3 cm in diameter, yellow-green, glabrous, apex acute. Pedicel 3–5 mm long, 2–3 mm in diameter, glabrous. Calyx white, 5-parted from the base, lobes equal, ovate-lanceolate, 1.2–1.6 cm × 0.3–0.4 cm, glabrous. Corolla white, with mauve lines and spots inside, 4–5.5 cm long, glabrous. Corolla tube 3.5–4.5 cm long, 1–1.4 cm in diameter at the mouth, 4–5 mm in diameter at the base, purple-spotted at throat, densely glandular-pubescent inside adaxial gibbous side of the tube, inside with a ring of hairs adnate to 7–8 mm above the corolla tube base; limb 2-lipped; adaxial lip 0.8–1.0 cm long, 2-lobed at apex, lobes equal, nearly semi-orbicular, abaxial lip 1–1.2 mm long, 3-parted, lobes subequal, oblong. Stamens 2, anthers fused by adaxial surfaces, adnate to 0.8–1 cm above the corolla base; filaments linear, glabrous, geniculate from the middle, 1.8–2 cm long, about 1 mm wide; anthers ovate-elliptic, glabrous, ca. 2–3 mm long, 2 mm wide, coherent at apex. Staminodes 2, glabrous, adnate to 1.2–1.5 cm above the corolla base, thick, 1.2–1.4 cm long, about 1 mm wide, apex capitellate, separate. Pistil 2–2.5 cm long; ovary linear, 0.7–0.9 cm long, 1.5–2.2 mm in diameter, glabrous; style 1.3–1.6 mm long, glabrous; stigma capitate, about 2 mm in diameter. Capsule linear-lanceolate, 2–3 cm long, 2–4 mm in diameter, glabrous, slightly curved.
Hemiboea albiflora is known from Maling River Valley and Pogang Nature Reserve, Xingyi City, Guizhou, China, growing on rock faces near Maling River and near streams in Pogang Nature Reserve, at an elevation of ca. 720–970 m.
Flowering occurs in August to October and fruiting in October to November.
The specific epithet refers to the corolla colour of this new species.
CHINA. Guizhou: Xingyi City, Maling River Valley, ca. 950 m alt., 12 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017060 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017062 (PE); Xingyi City, Maling River Valley, ca. 720 m alt., 12 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017057 (PE); Xingyi City, Maling River Valley, C.Y. Deng 3071 (XIN); Xingyi City, Pogang Nature Reserve, ca. 1000 m alt.,11 October 2018, X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017054 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017055 (PE), X.G. Xiang, Z.W. Wu & Z.Y. Guo 2017056 (PE).
To date, Hemiboea albiflora has two known populations of more than 300 and less than 1000 mature individuals, according to field observations. Both populations are endemic in karst areas and grow on rock faces or under forests near streams. The population, which is distributed in scenic spots and habitats, is susceptible to human activities, e.g. road construction or deforestation. The species is considered to be “Vulnerable” (VU D1) according to the IUCN Red List Criteria (
This study was supported by the National Natural Science Foundation of China (Grant no. 31370227, 31300181, 31670212), Special Funds for Traditional Chinese Medicine Industry (201407003), Major supporting funds for Characteristic subject of Qiannan Normal College for Nationalities (No. QNSY2018XK003) and the Natural Science Foundation of Guizhou Province of China ([2014]2156).