Primulina purpureokylin F.Wen, Yi Huang & W.Chuen Chou, 2019

Li, Shu, Xin, Zi-Bing, Chou, Wei-Chuen, Huang, Yi, Pan, Bo, Stephen Maciejewski, & Wen, Fang, 2019, Five new species of the genus Primulina (Gesneriaceae) from Limestone Areas of Guangxi Zhuangzu Autonomous Region, China, PhytoKeys 127, pp. 77-91 : 78-79

Primulina purpureokylin F.Wen, Yi Huang & W.Chuen Chou sp. nov. Fig. 1

Diagnosis.

Primulina purpureokylin most resembles P. leprosa (Yan Liu & W.B. Xu) W.B. Xu & K.F. Chung ( Fig. 6 A ) ( Xu et al. 2010, 2012) in having similarly purple indumentum on both surfaces of the leaf blade, but differs in having fewer leaves (4-6 in P. purpureokylin vs 5-12 in P. leprosa ; same order as following), smaller leaf blade size (2-6.5 × 1.5-3.5 cm vs. 6-13 × 4-8 cm), bracts shape (linear or linear-lanceolate vs broadly ovate), corolla color (pinkish purple vs. yellow) and length (1.5-1.8 cm long vs. ca. 2.3 cm long), staminodes number (2 vs 3) and indumentum of style (nearly glabrous vs glandular-pubescent).

Type.

CHINA. Pingguo County, Xin'an Town, Gusha village , 23°16'N, 107°29'E, 200 m a.s.l., growing on the surface and crevices of moist limestone rocks at the bottom of cliffs, 3 Apr 2018, Chou Wei Chuen et al. CWC171116-01 (holotype: IBK!, isotype: IBK!).

Description.

Perennial herbs. Rhizome subterete, 1-1.5 cm long, 5-10 mm in diameter. Leaves 4-6, all basal, opposite pairs; petiole compressed, cross section semi-elliptic, 1.5-2.5 cm long, 0.6-1.1 cm wide, shortly reddish purple to purplish brown strigose on both surfaces; blades dark green to purplish green, coriaceous or stiffly chartaceous, obliquely ovate, elliptic to broadly oblong-ovate, left-right asymmetric or symmetric, 2-6.5 × 1.5-3.5 cm, upper surface distinctly bullate, cuneate at base, commonly symmetric, occasionally oblique, margin entire, obtuse or rounded at apex, with erect reddish purple pubescence on both surfaces, margins with ciliate, pubescence 0.5-1 mm long, lateral veins 3 or 4 on each side, impressed adaxially and prominent abaxially. Cymes axillary, 2-4, 1- or 2-branched or single, 1- or 2-4-flowered on one cyme; peduncle 5.5-14.5 cm long, slender, 1-1.2 mm in diam., erect white glandular-pubescent; bracts 2, opposite, purplish green, linear or linear-lanceolate, ca. 6 × 1.5 mm, margin entire, acute at apex, sparsely purple puberulent outside, glabrous inside. Bracteoles 2, opposite, shape, hairs and color same as bracts but obviously smaller, ca. 3 × 0.8 mm. Pedicel 1-1.6 cm long, 0.8-1 mm in diam. Calyx 5-parted near to the base, lobes narrowly lanceolate-linear, 3-4 × 0.8-1 mm, margin entire, acute at apex, spreading white pubescent outside, glabrous nearly inside. Corolla pinkish purple, within 8-10 longitudinal dark purple stripes from corolla throat to the bottom of corolla tube, 1.5-1.8 cm long, spreading glandular puberulent outside, glabrous inside; tube tubular, pink, 8-9 mm long, 5-6 mm in diameter in medium, 5.5-6.5 mm in diam. at the mouth; limb distinctly 2-lipped, dark pink to purplish pink, adaxial lip 2-lobed to the middle, lobes ovate or nearly oblong, ca. 5 × 3 mm, obtuse to rounded at apex, with 2 or 3 deep purple lines inside; abaxial lip 3-lobed over the middle, two lateral lobes in apparently obliquely oblong, the central one zygomorphic, oblong, ca. 7 × 4 mm, rounded at apex. Stamens 2, adnate to ca. 5.5 mm above the base of the corolla tube; filaments white, geniculate at the middle, ca. 5.5 mm long, glabrous; anthers pale brown to purplish brown, subreniform, slightly contracted in the middle, ca. 1 mm long, glabrous. Staminodes 2, translucent, 0.8-1 mm long, glabrous, adnate to ca. 5 mm above the base of the corolla tube. Disc annular, ca. 0.7 mm high, margin entire. Pistil 1-1.1 cm long, ovary yellowish brown, linear, ca. 5 mm long, 0.8-1 mm in diam., glandular-puberulent; style white to translucent, 5-6 mm long, nearly glabrous; stigma obtrapeziform, ca. 0.9 mm long, apex 2-lobed. Capsule glabrous, valvate dehiscence when mature, 1.5-2 cm long.

Phenology.

Flowering in Nov., fruiting time in Dec.

Etymology.

The specific epithet, ' purpureokylin ', consists of two parts. The first part of the scientific epithet is " purpure -", means purple. It refers to the upper faces of the leaf blades which are covered in purple pubescent-hairs. The second half of the epithet, " kylin ", refers to one of the auspicious animals in the traditional culture of China. Because the interesting and beautiful leaves are full of purple-hairs, bubbles on the surface appear as if covered with the purple squamae of Kylin. The Chinese name is “Zí Líng Bào Chūn Jù Tái” (紫麟报春苣苔).

Distribution and habitat.

Primulina purpureokylin is currently known only from the type locality. Only a single population with ca. 100 individuals was discovered and confirmed. The species is only known growing on the surface and crevices of wet limestone rocks at the bottom of cliffs in Pingguo County, Guangxi, China.

Provisional IUCN conservation assessment.

Along with the further field investigations for the current survival situation of Primulina purpureokylin , the extinction risk of this species is rising because of over-harvesting by local plant collectors. Overexploited because of its beauty, this unpublished species is on the brink of extinction. Although more surveys are needed to clarify its conservation status, the provisional conservation status is Critically Endangered CR B2ab (iii, v) according to the IUCN red list criteria ( IUCN 2012).

Figures

Figure 1. Primulina purpureokylin F. Wen, Yi Huang & W. Chuen Chou sp. nov. A habit B cyme C frontal view of corolla D lateral view of corolla E dorsal view of corolla F ventral view of corolla G opened corolla for showing stamens, with pistil and calyx. Photographed by Wei-Chuen Chou and Yi Huang, charted by Wen-Hua Xu.

Figure 6. The morphologically similar congeners of the five new species of Primulina 1 habit 2 flowers. A P. leprosa, the congener of P. purpureokylin B P. gongchengensis, the congener of P. persica C P. renifolia, the congener of P. cerina D P. repanda, the congener of P. niveolanosa E P. longgangensis, the congener of P. leiyyi. Photographed by Fang Wen, charted by Wen-Hua Xu.