Primula sunhangii T. Deng, D. G. Zhang & Jiao Sun, 2020

Sun, Jiao, Zhang, Dai-Gui, Huang, Xian-Han, Tojibaev, Komiljon, Yang, Jing-Yuan, Wang, Heng-Chang & Deng, Tao, 2020, Primula sunhangii (Primulaceae): a new species from Hubei, Central China, PhytoKeys 156, pp. 103-112 : 103

Primula sunhangii T. Deng, D. G. Zhang & Jiao Sun sp. nov.

Type.

China, Hubei Province, Shennongjia Forestry District, Hongping, Dashuping. 31°26.67'N, 110°16.01'E Alt. 2877 m. 5 Jun 2011, D. G. Zhang et al. Zdg20110605023 (Holotype KUN!) (Fig. 1 ). - Isotype: China, Hubei Province, Shennongjia Forestry District, Hongping, Dashuping. 31°26.67'N, 110°16.01'E Alt. 2877 m. 5 Jun 2011, D. G. Zhang et al. Zdg20110605023 (JIU!).

Diagnosis.

Primula sunhangii is similar to P. involucrata in glabrous, efarinose, ovate leaves, and lanceolate bracts base prolonged below into auriculate appendage and its length. But it differs from P. involucrata in the following characters: glabrous sepal, cylindrical calyx and capsule, truncate or acute leaves base, and shorter scape (at most 3 times the leaves).

Description.

Herbs perennial, glabrous, efarinose. Leaves 5-10, all basal in a rosette; petiole green, basal white to pink, 1-5.6 cm long, 0.2-0.4 cm diam.; leaf blade green, ovate or oblong, 0.8-4.8 cm long, 0.5-2 cm wide, papery, base truncate or acute, margin entire or slightly denticulate, apex obtuse to rounded. Scapes 5-19 cm in length; umbels 2-4-flowered; bracts 5, lanceolate, 5-10 mm long, 1-3 mm wide, membranous, base prolonged below into 3-6 mm auriculate appendage. Pedicel 0.5-3.5 cm. Calyx 5-7 mm in length, 3 mm diam., cylindrical, parted to 1/4 to 1/3; lobes lanceolate, apex narrowly acute. Corolla funnel-form, pink or purple; tube 8-10 mm in length, 8-10 mm diam., limb 1-2 cm diam.; lobes obovate, deeply emarginated apex.

Pin flowers: corolla tube ca. 8.5 mm; stamens ca. 3.5 mm above base of corolla tube; the style is not or slightly exerted.

Thrum flowers: corolla tube ca. 1 cm; stamens toward apex of corolla tube; the style is slightly shorter than calyx.

Capsule cylindric, apex irregular dehisces. (Fig. 2 )

Distribution and habitat.

Fissures of rocks on mountain slopes; ca. 2,800 m. Shennongding (Hongping, Shennongjia, Hubei), Laojunshan (Muyu, Shennongjia, Hubei). (Fig. 3 )

Phenology.

Primula sunhangii flowers from June to July.

Etymology.

The specific epithet refers to the Chinese botanist Hang Sun.

Vernacular name: Simplified Chinese: 神农架报春; Chinese Pinyin: Shénnóngjià Bàochūn.

Conservation status and IUCN preliminary assessment.

The new species has only two known populations described thus far. The populations are both in subareas of Shennongjia, one in Shennongding and another in Laojunshan. Each population has ca. 40 individuals. The habitats are situated in a tourist attraction zone, with an average of 20,000 tourists visiting daily. According to IUCN red list categories and criteria, conservation status of this species should be Critically Endangered (CR) (B2abiii).

Relationship with related species.

Based on its glabrous, efarinose, ovate leaves, lanceolate bracts base prolonged below into auriculate appendage, and its length, P. sunhangii is most morphologically similar to P. involucrata ( Hu 1990; Hu and Kelso 1996). But P. sunhangii differs from P. involucrata in glabrous sepal, cylindrical calyx and capsule, truncate or acute leaves base, and shorter scape (at most 3 times the leaves). (Table 1 ).

We performed phylogenetic analyses using nuclear ITS as well as rbcL and matK of P. sunhangii and related species. Separate analyses for all three markers get six trees (ML and Bayesian) with similar structures. Combined molecular phylogenetic analyses shows that P. sunhangii and P. involucrata are sister taxa, with high support (Fig. 4 ). They have 19 different sites in the 2020 bp nucleotide sequence.

These genetic results and morphological data clearly support that Primula sunhangii be recognized as a distinct new species.

Figures

Figure 1. Holotype of Primula sunhangii T. Deng, D. G. Zhang & Jiao Sun, sp. nov.

Figure 2. Images of live Primula sunhangii T. Deng, D. G. Zhang & Jiao Sun, sp. nov. A habitat B inflorescence C leaves D flower, front and back side E toot. Scale bars: 1 cm in (C, D, E). Photographer: Qun Liu.

Figure 3. Distribution of Prunus sunhangii T. Deng, D. G. Zhang & Jiao Sun.

Figure 4. Bayesian tree of selected species in Primula, focused on Sect. Aleuritia. Based on a combined sequences from nuclear ITS and rbcL, matK of cpDNA genes. Numbers above the branches represent the Bayesian posterior probabilities, and below showing the maximum likelihood values. (* multifurcation in Maximum-likelihood tree).