Primulina yangchunensis Y. L. Zheng & Y. F. Deng

Primulina yangchunensis Y. L. Zheng & Y. F. Deng View in CoL , sp. nov. ( Fig. 1 View FIGURE 1 )

A P. orthandrae (W. T. Wang) Mich. Moller & A. Weber foliorum basi cuneatis, marginibus integris, utrinque hispidis, bracteis late lanceolatis 1–2 cm longis, corollae lilicinis, labio posico antico longioribus differt.

Type:— China. Guangdong: Yangchun Shi, Chunwan Zhen, Longgongdong , in crevice on vertical rock face, 12 December 2000, MO-IBSC Expedition to Hainan 635 (holotype IBSC! , isotypes BM! , MO! ).

Chirita yangchuensis Y.L. Zheng in Wei (2010: 462), nom. invalid.

Perennial herbs, stemless. Rhizome subteret, 1–1.5 cm long, ca. 0.5 cm in diameter, internodes inconspicuous. Leaves basal, opposite; petioles 2–5 cm, hispid; blades elliptic, 3–7 × 1.5–3 cm, papery, apex obtuse, base cuneate, margin entire and rugose, both surfaces hispid, lateral veins 4 or 5 on each side of midrib. Cymes 5–15-flowered. Peduncles 4–10 cm, pubescent. Bracts 2, opposite, free, broadly lanceolate, 0.8–2 × 0.2–0.5 cm, margin entire, pubescent. Pedicels 1–3.5 cm, pubescent. Calyx 5-lobed almost to the base, segments equal, lanceolate, 3–6 mm, outside pubescent, inside glabrous, margin entire, apex acute. Corolla pink, 1.5–2 cm, outside puberulent, tube narrowly funnel-form, 1.5–2 cm, mouth ca. 5 mm diam., adaxial lip 2–3 mm, 2-lobed, lobes broadly ovate, abaxial lip 5–7 mm, 3-lobed to near middle, lobes orbicular-ovate. Stamens 2, filaments ca. 5 mm, adnate to 8–12 mm above abaxial side of corolla tube base, erect, apex sparsely puberulent, anthers ca. 1 mm, glabrous, elliptic. Staminodes 2, ca. 3 mm, adnate to 6–9 mm above the base of corolla tube. Disc ring-like, ca. 1 mm. Pistil 1–1.5 cm, pubescent, ovary linear, 5–8 mm; style 4–6 mm, puberulent; stigma oblong, 2-lobed. Capsule linear, 2–3 cm.

Distribution and habitat:— Primulina yangchunensis is only known from the type locality, Longgongyan, Yangchun Shi, Guangdong Province, China. It grows on the rocks of a limestone hill at the elevation of about 100 m.

Conservation Red List Category:—Current information shows that the population size of this new species is less than 250 mature individuals from only one known site. We therefore assess it as “Critically Endandered” (CR) (B2a, C2a) using the IUCN Red List categories and criteria ( IUCN 2001, 2011).

Phenology:—The new species was observed on flowering from August to November and fruiting in January.

Etymology: — The new species is named after its type locality, Yangchun Shi, Guangdong Province, China.

Relationship:—This new species is similar to Primulina orthandra ( Wang 1985b: 42) Mich.Moller & A. Weber in Weber et al. (2011: 784), from which it differs in leaf blade base cuneate, margin entire and rugose, both surfaces hispid, bracts broadly lanceolate, 1–2 cm long, and the length of the abaxial lip obviously longer than that of the adaxial lip. Primulina orthandra has leaf blade base oblique cuneate, margin densely crenulate to dentate or serrulate, both surfaces densely puberulent, bracts ca. 5 mm, ovate, and the abaxial lip of corolla slightly longer than that of the adaxial lip. The morphological comparison is shown in table 1.

Additional specimens examined (Paratypes):— CHINA. Guangdong: Guangzhou, cultivated in South China Botanical Garden, introduced from Yangchun Shi , 20 August 2002, Zheng Yongli 401 ( IBSC) ; Yangchun Shi, Chunwan Zhen, Lingxiaoyan , 25 August 2011, Zheng Yongli 201108001 ( IBSC) .