Primulina persica 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 : 80-82

Primulina persica F.Wen, Yi Huang & W.Chuen Chou sp. nov. Fig. 2

Diagnosis.

Primulina persica most closely resembles P. gongchengensis Y.S. Huang & Yan Liu ( Fig. 6 B ) ( Huang et al. 2012) in having similarly shaped leaf blades. It differs from the latter by having a different indumentum on both surfaces of the leaf blades (densely eglandular-pubescent in P. persica vs densely glandular-pubescent in P. gongchengensis ; same order as following), margin of leaf blade (irregularly serrate in different numbers vs. repand or crenate), smaller bracts (6-7 × 1.5-2 mm vs. 10-20 × 2-3.5 mm) and bracts shape (linear vs. narrowly rhombic to oblong), the indumentum of calyx lobes inside (glabrous vs sparsely glandular-pubescent) and shorter corolla length (7.5-10 mm long vs. 22-28 mm long).

Type.

CHINA. Yangshuo County, Gaotian Town, Lexiang village , 24°42'N, 110°30'E, 124 m a.s.l., growing on the surface of tufa and crevices of moist rocks on a cliff of a limestone hill, 3 Apr 2018, Chou Wei Chuen et al. CWC171116-01 (holotype: IBK!, isotypes: IBK!)

Description.

Perennial herbs. Rhizome subterete, 5-6 cm long, 8-10 mm in diam. Leaves 6-10, crowded at apex of rhizome, petiolate; petiole cylindrical, upper slightly smaller and the bottom slightly inflated but the base slightly applanate, 8-15 cm long, 6-8 mm in diam. at base, densely eglandular-pubescent; leaf blade herbaceous, rhomboid-ovate or elliptic, 6-11 × 5-9.5 cm, apex acute, obtuse or slightly round, base cordate, broadly cuneate to cordate, slightly inequilateral, margin irregularly serrate in different numbers, densely pubescent on both surfaces, lateral veins 2 or 3 on each side, impressed adaxially and prominent abaxially. Cymes 4-10, 1-3-branched, 12-30-flowered; peduncle 12-20 cm long, 2-2.5 mm across, densely glandular-pubescent; pedicel 1-3 cm long, densely glandular-pubescent; bracts opposite, linear, 6-7 × 1.5-2 mm, margin entire, apex acute, adaxially glandular-puberulent, abaxially nearly glabrous. Calyx 5-parted nearly to base, lobes narrowly lanceolate, 4.5-5.5 × ca. 1 mm, margin entire and ciliolate, outside densely glandular-pubescent, inside glabrous. Corolla pinkish, fuchsia to pale purple, 7.5-10 mm long, 4-4.5 mm in diam. at mouth, outside glandular-puberulent; tube short, 5.5-6.5 mm long, ca. 4.5 mm in diam. in middle, tube base slightly swollen, ca. 2 mm in diam. at base; limb distinctly 2-lipped, adaxial lip 2-lobed to more than the middle, lobes oblong, apex round, 3.2-3.8 × 2.5-3 mm, abaxial lip 3-lobed to more than the middle, lobes oblong, apex round, 4.5-5.2 × 3.3-3.6 mm. Stamens 2, adnate to 2.5 mm above corolla tube base, filaments 4-4.5 mm long, curved at middle, anthers elliptic or reniform, ca. 1.5 mm long, glabrous; staminodes 3, lateral ones 0.8-1 mm long, adnate to 1.8-2 mm above corolla tube base; middle one 0.5 mm long, adnate to ca. 1.3 mm above corolla tube base. Disc annular, ca. 0.6 mm in height, margin entire. Pistil 6.5-7.5 mm long, ovary ovoid, ca. 2.5 × 1.3-1.5 mm, glandular-puberulent; style indumentum same as ovary, 4-5 mm long, ca. 0.5 mm in diam. in the middle; stigma obtrapeziform, ca. 0.8 mm long, apex 2-lobed. Capsule ovoid, ca. 8 mm long, valvate dehiscence when mature, outside pubescent.

Phenology.

Flowering from May to June; fruiting from June to August.

Etymology.

The specific epithet, ' persica ', refers to the color of its flower, a vivid and bright peach. The Chinese name is “Tāo Hóng Xiáo Huā Jù Tái” (桃红小花苣苔).

Distribution and habitat.

Primulina persica is currently known only from the type locality and only about 50 individuals were confirmed. All individuals are growing on the surface of tufa and wet crevices of moist rocks on the cliff of a limestone hill in Yangshuo, Guangxi, China. There are no accompanying plants except for some ferns.

Provisional IUCN conservation assessment.

The original habitat of this species was almost destroyed because of road building in 2013; it directly resulted in a single small population with no more than 50 surviving individuals. We hope we can find more populations in the future through field surveys. The habitat of Primulina persica is likely to be subjected to human activities because the survival population grows in cracks of a limestone cliff by the side of the road. Thus, based on currently available information, P. persica should be considered as 'Critically Endangered’ (CR): B1+2ab(V); C2b, following the IUCN categories and criteria ( IUCN 2012).

Figures

Figure 2. Primulina persica F. Wen, Yi Huang & W. Chuen Chou sp. nov. A habitat B habit C plant in flower, cultivated in GCCC D adaxial surface of leaf E abaxial surface of leaf F cyme and flowers G front view of corolla H lateral view of corolla I opened corolla for showing stamens J dorsal view of corolla K adaxial surface of calyx lobes L pistil. Photographed by Fang Wen, 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.