Primula pingbaensis Na Zhang, X.Q.Jiang & Z.K.Wu, 2023

Zhang, Na, Jiang, Xiao-Qi & Wu, Zhi-Kun, 2023, Primula pingbaensis (Primulaceae), a new species from Guizhou, China, PhytoKeys 221, pp. 85-93 : 85

Primula pingbaensis Na Zhang, X.Q.Jiang & Z.K.Wu sp. nov.

Figs 1A-I , 2

Note.

The new species most resembles Primula esquirolii and P. coerulea , sharing similar floral morphology and short or almost obsolete scapes at flowering time. However, the new species differs from the homostylous P. esquirolii mainly in its lamina smooth on upper surface, deeper flower color, oblong flower lobes, and the style usually extending beyond the anthers. Compared to the heterostylous P. coerulea , the new species differs mainly in its homostylous flower, and the whole plant is usually covered with sparse glands. The main morphological distinctions between P. pingbaensis , P. esquirolii and P. coerulea are summarized in Table 1 .

Type.

China. Guizhou: Pingba county, Gaofeng Mountain , Wanhua Temple. 26°22'31"N, 106°24'24"E, 1432 m alt., 14 January 2021 (fl.), ZKWU 2021010 (holo-type: GZTM!) .

Description.

A perennial slender, dwarf herbaceous, efarinose, with a short rhizome and numerous fibrous roots. Leaves forming a rosette, at flowering time 2-4 cm long including the petiole, 2-3 cm broad, spatulate or elliptic-obovate, obtuse or rounded at the apex, gradually tapering into the winged petiole; petiole up to 1/3 as long as leaf blade; lamina thin papery, upper surface smooth, lower surface midrib conspicuous but reticulate veins inconspicuous, sparsely glandular, margin with regular sparsely acute serrate. Scape at flowering time almost obsolete, to 1 cm in fruit, sparsely glandular, usually 1-3 flowered. Bracts linear-lanceolate, 3-6 mm long, sparsely glandular; pedicel 5-12 mm, glandular. Flower homostylous; calyx campanulate, 5-6 mm long, glandular-puberulous, parted nearly to 1/3 of its length, lobes triangular-lanceolate, apex acute; corolla funnel-shaped, violet, tube 13-15 mm long, usually three times the length of the calyx, limb 15-20 mm wide, lobes oblong, 4-6 mm long, apex emarginate; stamens with anthers 1.5 mm long, inserted at apex of corolla tube, style 14-15 mm long, usually beyond the anthers. Capsule subglobose, 4-6 mm in diameter, nearly equal to calyx.

Distribution and ecology.

Primula pingbaensis is only known from the type locality on Gaofeng mountain in Pingba county, Guizhou, China. The plant grows on moist walls of karst cliffs. (Fig. 1 , Map 1 ).

Phenology.

Flowering occurs from January to March; fruiting from April to June.

Etymology.

The epithet of the new species is derived from the name of Pingba county, Guizhou, where the new species was discovered and collected (Map 1 ).

Vernacular name.

Chinese mandarin: ping ba bao chun (平坝报春).

Provisional conservation status.

Critically Endangered (CR B2ab(iii)). Field surveys were conducted several times in the type locality and adjacent districts for this new species, and only one population of Primula pingbaensis was discovered, with ca. 40-60 adult individuals, distributed over about 100 m2 in the type locality. This site is on the grounds of a temple, and some individuals grow close to the path for visitors and face a strong threat from human activities. Its status should therefore be of concern and addressed in further investigations.

We estimated the extent of occurrence of the species to be less than 100 km2. Over the last four years, we have observed a steady decline in the territory area of the habitat due to the temple building maintenance and road construction. Considering the present field information and IUCN categories of threat, this species should be included in the category Critically Endangered (CR B2ab(iii)).

Figures

Figure 1. A-I Primula pingbaensis sp. nov.: A habitat B habit in flowering C capsule in early-fruiting D capsule in later-fruiting E flower, front view F bracts and calyx G calyx and stigma H dissected corolla showing the anthers and stigma I specimen in flowering; J-L Primula esquirolii: J habitat K leaves, both surfaces L habit. Photographed by Z. K Wu.

Map 1. Location of the population of Primula pingbaensis in Pingba county.

Figure 2. Primula pingbaensis sp. nov. A habit B calyx and stigma C upper face of leaves D lower face of leaves E dissected corolla F capsule. Drawn by Ms. Xiang-Li Wu.