Primulina leiyyi F.Wen, Z.B. Xin & 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 : 87-89

Primulina leiyyi F.Wen, Z.B. Xin & W.Chuen Chou sp. nov. Fig. 5

Diagnosis.

Primulina leiyyi most closely resembles P. longgangensis (W.T. Wang) Yan Liu & Y.Z. Wang ( Fig. 6 E ) ( Wang and Huang 1982, Wang et al. 2011, Weber et al. 2011) in having similarly shaped leaf blades, but differs in their indumentum of young stems (sparsely appressed hazel pubescent in P. leiyyi vs. nearly glabrous in P. longgangensis ; same order as following), shape of bracts (elliptic to cymbiform vs. linear to lanceolate or obovate), indumentum of corolla (outside sparsely glandular-puberulent, inside glabrous vs. outside glabrous to puberulent, inside puberulent or glabrous below stamens), pistil length (1.8-2.0 cm long vs. ca. 2.8 cm long) and capsule length (4.8-5.5 cm long vs. 1.6-2.5 cm long)

Type.

CHINA. Nanning city, Suxu Town , Shibaluohandong village , 22°32'N, 108°3'E, 150 m a.s.l., growing on the top of limestone cliff near road, 3 Apr 2018, Lei YuYang et al. LYY181208-01 (holotype: IBK!, isotypes: IBK!)

Description.

Perennial herbs. Rhizome cylindrical, the long rhizome up to 50 cm long or longer and branched repeatedly after several years of growth, 5-6 mm in diam.; branch up to 8-15 cm long, sparsely appressed hazel pubescent when young, gradually glabrous when mature. Leaves ternate, occasionally opposite, subsessile to sessile; leaf blade fleshly to thickly herbaceous when fresh, hard chartaceous when dried, often asymmetric, obliquely oblanceolate to broadly ensiform, 6.5-16 × 1.5-2.5 cm, apex acuminate to acute, base narrowly cuneate, gradually attenuated to be petiole, margin entire, adaxially and abaxially densely appressed pubescent and strigose, lateral veins 4 or 5 on each side, slightly impressed adaxially and apparently prominent abaxially. Inflorescences axillary, cymes 2-6 on the near top of every branch, 1-branched, (1)2-6-flowered per cyme; peduncle reddish brown, 3-7.5 cm long, 1-1.5 mm in diam., densely spreading eglandular-pubescent; bracts 2, opposite, green to yellowish green, elliptic to cymbiform, 1.2-2.3 cm × 3-6.5 mm, margin entire, apex acuminate to acute, adaxially and abaxially densely appressed pubescent; pedicel reddish brown, 2-3 cm long, ca. 1 mm in diam., indumentum same as peduncle. Calyx 5-parted to base, lobes reddish brown, narrowly lanceolate-linear to linear, ca. 8 × 0.3 mm, margin entire, outside densely puberulent, inside nearly glabrous. Corolla dark pink to purplish pink, ca. 3.5 cm long, 11-12.5 mm in diam. at mouth, outside sparsely glandular-puberulent, inside glabrous; tube tubular, 2.4-2.8 cm long, 3-3.5 mm in diam. at the middle, tube slightly upswept, base gradually constricted, 2.5-3.5 mm in diam. at base; limb distinctly 2-lipped, adaxial lip 2-lobed to over middle, slightly obliquely oblong, apex rounded, 4.5-5.5 × 3.8-4.5 mm, abaxial lip 3-lobed to about middle, lateral ones slightly obliquely oblong, 6.5-7.5 × ca. 4.5 mm, central one oblong, apex rounded, 7.5-8 × 6.5-7 mm, mm. Stamens 2, adnate to ca. 7 mm above corolla tube base, filaments white, 8-9 mm long, geniculate at middle, anthers white, reniform to fusiform, ca. 3 mm long, nearly glabrous; staminodes 3, lateral translucent to white, ones adnate to 6.2-6.5 mm above corolla tube base, 4-4.5 mm long, apex capitate, central one adnate to 4.8-5 mm above corolla tube base, small, punctate, ca. 1 mm long. Disc annular, white, 0.8-1 mm in height, margin entire. Pistil 1.8-2.0 cm long, ovary reddish brown, cylindric, 9-10 mm long, 1-1.3 mm in diam., densely white glandular-puberulent; style 9-10 mm long, 0.6-0.7 mm in diam., pale reddish brown from case to middle, white from middle to top, densely glandular-puberulent; stigma obtrapeziform, ca. 1.2 mm long, apex 2-lobed, lobes truncate. Capsule linear, valvate dehiscence and glabrous when mature, 4.8-5.5 cm × 2.2-2.5 mm.

Phenology.

Flowering from November to the beginning of December; fruiting in January of the next year.

Etymology.

The new species is named after Mr. Yu-Yang Lei, who first discovered and collected this rare species and who accompanied us on a number of subsequent field expeditions in Nanning, Guangxi. The Chinese name is “Léi Shì Bào Chūn Jù Tái” (雷氏报春苣苔).

Distribution and habitat.

It is currently known only from the type locality in a single population with ca. 100 individuals. Although it might be endangered, more surveys are needed to clarify its conservation status. The species is only known growing on the surface of wet rocks on the limestone hills along the edges of village roads.

Provisional IUCN conservation assessment.

We carefully explored the type locality on five visits over a period of three years. Primulina leiyyi appears to be restricted to limestone hills surrounding Shibaluohandong village, Suxu Town, Nanning city. Although the habitats are very near to densely populated areas and are easily threatened by human activities, this species is common and locally abundant on limestone hills. Using the IUCN Red List categories ( IUCN 2012), a provisional conservation status of Least Concern (LC), is assessed for this species.

Figures

Figure 5. Primulina leiyyi F. Wen, Z. B. Xin & W. Chuen sp. nov. A habit B cyme and flowers C plant in flower collected in the field D extended branches after growing for one or some years E adaxial and abaxial view of leaf blades F cyme with one flower near top of stem G pubescent hairs on the surface of stem H different cymes with variable numbers of flowers I bracts J lateral view of bud K opened corolla for showing stamens and staminodes L pistil without calyx lobes M adaxial surfaces of calyx lobes N mature capsules. 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.