Primulina hengshanensis L.H. Liu & K.M. Liu, 2018

Tian, Jing, Liu, Lei, Xiao, Shun-Yong, Zhu, Xiao-Wen, Wu, Yao-Jing, Zhou, Liu, Yin, Juan, Pen, Ling, Cai, Xiu-Zhen, Liu, Lin-Han, Liu, Ying-Ding & Liu, Ke-Ming, 2018, Primulina hengshanensis (Gesneriaceae), a new species from Danxia landform in Hunan, China, Phytotaxa 333 (2), pp. 293-297 : 293-294

Primulina hengshanensis L.H. Liu & K.M. Liu , sp. nov. (see Figs. 1–2 )

Diagnosis: — Primulina hengshanensis is similar to P. langshanica , but differes from the latter by its leaf broadly oval to reniform, or rounded, 9.7–22.3 × 9.0– 22 cm; petiole flat and inconspicuous, 1.0–2.5 × 2.0– 3.5 cm; pinnately-nerved; Cymes 2–10 or more, 2–3- branched, 2–15(–30)-flowered; peduncle 8–31 cm long (see also Table 1).

Type: — CHINA. Hunan Province: Hengshan County, Heyun Village , 27°22 ′ N, 112°40 ′ E, elevation ca. 107.5 m. 2 August, 2015, K. M. Liu, L. Liu & L. H. Liu 34218 (holotype, HNNU!; isotypes, HNNU!, CSFI!) .

Perennial herb, acaulescent. Rhizome subterete, 3–6 × 1.7–2.9 cm. Leaves 4–8, fleshy (papyraceous when dry), all basal, opposite; petiole flat, 1.0–2.5 × 2.0– 3.5 cm (young leaves nearly sessile), green or reddish violet, densely pilose; leaf blade broadly oval to reniform, or rounded, 9.7–22.3 × 9.0– 22 cm, adaxial leaf surface covered with white bristles, abaxial surface densely pubescent, base oblique, margin repand to denticulate, apex obtuse to rounded; lateral veins 4–5 on each side of midrib, adaxially impressed, abaxially prominent. Cymes 2–10 or more, 2–3-branched, 2–15(–30)-flowered; peduncle 8.0– 31 cm long, densely pubescent; bracts 2, ovate-oblong, ca. 4.0 × 1.3 cm pale to green, apex acuminate, margin with 2–4 teeth, outside densely pubescent, inside sparsely pilose, midrib conspicuous; pedicel 1.0– 4.2 cm long, densely covered with glandular trichomes. Calyx 5-parted to base; lobes lanceolate, 9–12 × 1–1.5 mm, margin entire, outside puberulent, inside glabrous. Corolla pale purple or pale bluish purple, ca. 5 cm long, outside with short glandular trichomes, inside covered with short glandular trichomes; tube narrowly funnel-shaped, ca. 3.4 × 1.2 cm, slightly curved; limb distinctly 2-lipped, adaxial lip 2-lobed, ca. 8.3 mm long, abaxial lip 3-lobed, lobes oval, the central longer than the other two, 9–10 mm long. Stamens 2, adnate to 2.2 cm above the base of corolla tube; filaments ca. 12 mm long, geniculate at middle; anthers ca. 4.5 mm long, anther sac coverd with long glandular trichomes; staminodes 2, rarely 3, 2.8 mm long, capitate and curved at apex, adnate to 1.5 cm above the base of tube. Disc annular, 1 mm high. Pistil ca. 3.4 cm long; ovary ca. 1.8 cm long, style ca. 1.4 cm long, all with short pubescence and a sparse covering of glandular trichomes; stigma linear, ca. 3 mm long, 2-lobed, Capsule ca. 3.5–5.3 cm long, slightly curved, densely pilose. Seeds brown [all measurements where taken from plants growing in the wild, not from cultivated material].

Phenology: —Flowering form July to September and fruiting from August to November.

Etymology: —The specific epithet is derived from the administrative unit the type locality is part of.

Distribution and ecology: —The new species is only known from Heyun Village in Hengshan County, Hunan Province, China. It grows on limestone, on cliffs or on the edge of caves of the Danxia landform, at about 100 m elevation. It is associated with Selaginella uncinata , Siphonostegia chinensis , Patrinia villosa , Commelina communis , Lygodium japonicum , Ampelopsis glandulosa , Chrysanthemum indicum and Mosla scabra .

Conservation status and assessment: —There are 4 populations (about 350 individuals) of this species. The populations regenerate well. Ecological environment of the Danxia landform is fragile, once damaged will be unsustainable. Many individuals occur close to a road at a popular scenic spot. Thus, they are easily affected by people. So we suggest that this species is VU B1ab(i,iii)+2ac(ii,iv); D2. ( IUCN 2012).

Taxonomic placement: —According to with rhizome subterete, without aerial stem, with bracts 2 opposite and so on, to judge the new species is similar to Primulina langshanica , but it differs from the latter one by numerous characters which are summarized in Table 1 (see also Fig. 2 ).

Figures

FIGURE 1. Primulina hengshanensis L.H. Liu & K.M. Liu: (A) habit (includes 6 Inflorescences); (B) opened corolla exposing stamens and staminodes; (C) calyx; (D) pistil; (E) capsule; (F) rhizome. (Drawn by Jing Tian)

FIGURE 2. Primulina hengshanensis L.H. Liu & K.M. Liu: (A) and (B) habitat; (C) mature plant; (D) rhizome subterete; (E) adaxial leaf surface; (F) abaxial leaf surface; (G) inflorescence; (H) dissected flower; (I) pistil and calyx lobes. P. langshanica Wang: (J) mature plant; (K) inflorescence.