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| Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou, in Xin, Fu, Huang, ... et Zhou, 2020. |
Abstract
A new species, Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou, from NW Guizhou, China, is described and illustrated here. It shares a rare characteristic with P. hunanensis X.L. Yu & Ming Li, P. tongziensis R.B. Zhang & F. Wen and P. longitubus Cong R. Li & Yang Luo: all have four fertile stamens, a character state distinguishing this clade from the rest of Petrocodon. P. chishuiensis closely resembles P. hunanensis and P. tongziensis, but differs in vegetative and generative characters. We found only one population with no more than 60 mature individuals at the type locality. This species is provisionally assessed as Critically Endangered (CR B2ab(iii)) using IUCN criteria.
Keyword: China, Cliff-dwelling, Danxia landform, Flora of Guizhou, Gesneriaceae, Petrocodon, taxonomy
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| Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou: A: habit; B: cut open corolla with four stamens; C: upper stamens; D: lower stamens; E: pistil with bracteoles and opened calyx; F: stigma and part of style; G: mature dehisced capsule. From F.W.-Ges 20101001(IBK). Drawn by Yun-Xi Zhu. |
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| Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou: A: habitat; B: plants in flower and leaf blade adaxial surface; C: leaf blade abaxial surface; D: Frontal view of flower, showing the two rows of conspicuous orange-yellow glandular hairs on lower lip and corolla throat; E: lateral view of flower; F: flower viewed from below; G: pistil, showing the stigma, style and ovary; H: mature, dehisced capsule splitting into 4 valves. (Photos: Fang Wen). |
Petrocodon chishuiensis Z.B. Xin, F. Wen & S.B. Zhou,
sp. nov.
赤水石山苣苔
Diagnosis. Petrocodon chishuiensis is morphologically
similar to P. hunanensis (Fig. 3), but differs by its
acaulescence (vs. stem 5–20 cm long); leaf blades thin
chartaceous, oblong or oblanceolate, 5–7 cm long (vs.
thickly chartaceous, ovate, 2–3.2 cm long); petiole 3–8
cm long, densely white lanate (vs. 0.5–2.5 cm long,
densely reddish-purple pubescent); bracts oblong, 7–12
mm long (vs. lanceolate, 1–3 mm long); calyx lobes linear,
9–10 × ca. 1 mm (vs. triangular-lanceolate, 3–5 × ca. 1
mm); staminode absent or extremely indistinctive (vs. ca.
1 mm long); ovary 18–20 mm long, no stipitate (vs. ca. 10
mm long, distinctly stipitate) and capsule glabrous (vs.
densely short puberulence). P. chishuiensis also resembles P. tongziensis (Fig. 4) but differs by its leaf blades
oblong or oblanceolate, 5–7 cm long (vs. elliptic to ovalelliptic, 2.5–4.5 cm long); bracts 2, oblong, 7–12 mm
long (vs. bracts 3, oval-lanceolate, 1–2 mm long); calyx
lobes linear, 9–10 × ca. 1 mm (vs. linear-lanceolate, 3–5
× ca. 0.5 mm); corolla white with pinkish shading, with
2 conspicuous rows of orange-yellow glandular hairs on
abaxial lip (vs. pale violet with a lavender shading, a
darker purple blotch on abaxial lip); ovary linear, 18–20
× 0.8–1.3 mm (vs. cylindrical, ca. 8 × ca. 2 mm); fruit 5–
6.5 cm long (vs. 1.5–2.5 cm long) and capsule glabrous
(vs. densely short puberulence).
Etymology: The specific epithet is derived from the
type locality, Chishui City, Guizhou Province, China.
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| Petrocodon hunanensis: A: habitat; B: plants in flower; C: shoots with a single flowered cyme and stem with distinct internodes; D: leaf blade adaxial surface; E: leaf blade abaxial surface; F: frontal view of corolla; G: lateral view of corolla; H: flower viewed from below; I: stigma, style and distal part of the ovary; J: calyx lobes, disc and stiped ovary. (Photos: Xun-Lin Yu, Jian-Jun Zhou & Ming Li). |
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| Petrocodon tongziensis: A: habitat; B: plant in flowering; C: the frontal view of corolla; D: the lateral view of corolla; E: abaxial and adaxial surfaces of leaf blades and petiole; F: pistil. (Photos: Ren-Bo Zhang.) |
Zi-Bing Xin, Long-Fei Fu, Zhang-Jie Huang, Shu Li, Stephen Maciejewski, Fang Wen and Shou-Biao Zhou. 2020. Petrocodon chishuiensis (Gesneriaceae), A New Species Endemic to Guizhou, China. Taiwania. 65(2); 181-186.
