Primula xingshanensis Y. B. Wang, 2023

Wang, Shi-Qin, Yan, Hai-Fei, Cheng, Zhi-Jie & Wang, Yu-Bing, 2023, Primula xingshanensis (Primulaceae), a new species from Hubei, China, Phytotaxa 594 (2), pp. 158-162 : 158-160

Primula xingshanensis Y. B. Wang , sp. nov.

( Fig. 1 ).

Type.— CHINA. Hubei Province, Yichang City, Xingshan County, Xiakou Town , on rocks, elev. 360 m, 31°12´N, 110°51´E, 27 Feb 2022, Wang et al. ycmy152 (holotype, IBSC!, isotypes, PE!) .

Description:— Perennial herb, up to 30 cm tall, leaves and stems with dense long hairs. Roots dark brown or lilac, fleshy and brittle. Rhizomes brown, 3–22 cm long, sometimes branched, comparatively stout, with numerous dry leaf sheath, old and young leaves at apex. Leaves 5–12, rosette; petioles 1.3–4.8 cm long, green with copious multicellular white hairs, vaginate at base; blades obovate-spatulate to spatulate, 2–5 × 1–3 cm, fleshy, densely white villous on both sides, adaxially green, abaxially light green, pinnately lobed to ca. 1/3 of its width; lobes 7–10, oblong to subrotund, margin entire; cuneate at base, round at apex, lateral veins 4–6 pairs. Scapes 2–3 arising from each leaf rosette, 2.2–6.2 cm tall, densely white villous, umbels 1–3, superimposed, each umbel with 2–5 flowers; bracts linear to lanceolate, 0.3–1.5 cm long, acute at apex, densely white villous; pedicels 1.2–3.0 cm long, densely white villous. Flowers heterostylous; calyx bell-shaped, 6–9 mm long, 5–7 mm in diam., inflated at base in fruit, densely white villous, parted to 1/3, lobes triangular, margin entire, apex acute; corolla pink or pale lilac, funnel-shaped, with yellow spots at throat; limb 2.5–4.0 cm in diam., lobes 5, broadly elliptic, ca. 10 × 9 mm, glabrous, 2-lobed at apex, parted to 1/3. Pin flowers with corolla tube ca. 1–1.3 cm long, stamens inserted 3–4 mm from base of corolla tube, pillar length about 3/4 of corolla tube, 6–9 mm long, slightly higher than the calyx; thrum flowers with corolla tube 1.2–1.4 cm long, stamens inserted 6–8 mm from base of corolla tube, pillar 3 mm long. Stigma globular; ovary globular, glabrous, ca. 3.5 mm in diam., ovules many. Capsule subglobose, 5–6 mm in diam. Seeds many, ellipsoid, 1–2 mm long.

Phenology:— The species was observed flowering from February to March, and fruiting from the end of March to April.

Etymology:— The specific epithet refers to the Chinese pinyin of Xingshan County, where is the type locality.

Distribution and ecology:— The new species is currently only known from Xiakou Town, Xingshan County, Yichang City, Hubei Province, China, growing on the rock ledges of rocky cliffs of limestone at about 360 m a.s.l., where there is without soil and moisture due to exposure to the sun. Companion species, such as Corydalis saxicola Bunting , Triaenophora shennongjiaensis X. D. Li, Y. Y. Zan & J. Q. Li , Silene dentipetala H. Chuang can be found around.

Conservation status:— To date, only one population with ca. 1000 individuals of the new species has been found. The habitat is free from human disturbance, but the conditions are very poor (nearly without soil or moisture). Based on present survey and according to IUCN red list criteria ( IUCN 2001), its conservation status is assessed as ‘Critically Endangered’ (CR)(B2abiii).

Taxonomic Note:— According to Hu (1996), Primula xingshanensis should be placed in P. sect. Auganthus because of its distinctively broad and flat-bottomed calyx. Primula xingshanensis is morphologically most similar to P. rupestris in the broad and flat-bottomed calyx and rhizomes with persistent old leaves at the apex and has an overlapping geographical distribution with the latter (West Hubei versus West Hubei and South Shaanxi), but can be easily distinguished by leaf base (cuneate versus cordate or sub-truncate), leaf lobation pattern (pinnately lobed versus palmately lobed) and petiole length (1.3–4.8 cm versus 4–13 cm). The new species is also similar to P. sinensis from Guizhou and Sichuan, but P. xingshanensis clearly differs in its old leaves remaining at the apex of the rhizomes (versus without old leaves at apex), green petiole 1.3–4.8 cm long (versus purplish petiole 4–15 cm long), cuneate leaf base (versus cordate or sub-truncate) and pinnately lobed leaf blade (versus palmately lobed). Here, to facilitate its identification, we provided photographs ( Figs. 1 & 2 ), a detailed morphological comparison ( Table 1 ), as well as a key to the species of Primula sect. Auganthus .

Figures

FIGURE 1. Primula xingshanensis. A. habitat, B. flowering plants, C. plant with persistent old leaves, D. plant with roots and rhizomes, E. longitudinal section of thrum flower (left) and pin flower (right), F. leaves, adaxial (right) and abaxial (left) surface, G. bract, H. rhizomes, showing persistent leaf sheaths, I. root, J. androecium, K. infructescences, L. young fruit, M. ripe fruits, N. ripe seed. PhotosA–L:Yu-Bing Wang, M–N: Zhi-Jie Cheng.

FIGURE 2. Photographs of Primula xingshanensis, P. rupestris and P. sinensis. A. P. xingshanensis, B. P. rupestris, C. P. sinensis. A 3: holotype of P. xingshanensis (barcode IBSC0895005), B 3: holotype of P. rupestris (E barcode E00024352), C 3: lectotype of P. sinensis (BM barcode BM000996827). Photo credit: A 3 and B 2: Shi-Qin Wang, C 2: Hai-Fei Yan, the rest: Yu-Bing Wang.