Primulina pingleensis Ying Qin & Yan Liu, 2022

Qin, Ying, Meng, Tao, Chen, Hai-Ling & Liu, Yan, 2022, Primulina pingleensis (Gesneriaceae), a new species from Guangxi, China, Phytotaxa 532 (2), pp. 176-182 : 177

Primulina pingleensis Ying Qin & Yan Liu , sp. nov. ( Fig. 1 )

Type:— CHINA. Guangxi Zhuang Autonomous Region : Guilin City , Pingle County, Yuantou Town , elev. 176 m, 15 August 2021, Ying Qin GXQY20210815001 (holotype: IBK!, isotypes: IBK!, PE!) .

Diagnosis:—The new species is similar to P. pseudoheterotricha ( T. J. Zhou, B. Pan & W. B. Xu in Pan et al. 2009: 596) Mich. Möller & A. Weber in Weber et al. (2011: 784) and P. macrodonta (D. Fang & D. H. Qin in Fang et al. 1994: 566) Mich. Möller & A. Weber in Weber et al. (2011: 783), but is easily distinguished from the former mainly by its broadly cordate or suborbicular (vs. elliptic or ovate to broadly ovate) leaves, strongly laterally compressed (vs. broadly tubular) tube, deeply bilobed (vs. shallowly bilobed) stigma, and from the latter mainly by its strongly laterally compressed (vs. not compressed) tube, densely glandular-puberulent (vs. glabrous) filaments, glabrous and divergent (vs. densely bearded and elliptic) anthers.

Perennial herbs. Rhizome 12–69 cm long, 1.2–3.9 cm in diameter, with 6–39 leaves. Leaves herbaceous, crowded at apex of rhizome; petiole terete, 12–32 cm long, 0.2–1.2 cm in diameter, densely yellow glandular-puberulent; blade broadly cordate or suborbicular, 6.5–23.0 cm long, 7.2–24.0 cm wide, base cordate, margin shallowly to deeply lobed, lobe margin irregular serrate, both surfaces densely yellow glandular-puberulent. Cymes axillary, 3–5-branched, each cyme 6–49-flowered; peduncle 18–43 cm long, 1–3 mm in diameter, densely yellow glandular-puberulent; bracts 3, narrowly lanceolate to broadly lanceolate, 1.1–3.2 cm long, 3.5–11.0 mm wide, densely yellow glandular-puberulent, green, reflexed, margin toothed or nearly entire and slightly crinkled. Pedicel 1.9–4.1 cm long, densely yellow glandularpuberulent. Calyx 5-parted from base; lobes narrowly lanceolate, 5.5–10.0 mm long, 1.0– 1.3 mm wide, densely yellow glandular-puberulent. Corolla pale purple-red to purple-red or white, pale yellow-green to pale yellow-white at base, sparsely yellow glandular-puberulent outside; tube 1.5–1.9 cm long, strongly laterally compressed, sparsely glandularpuberulent along the fusion parts of filaments and corolla inside, orifice narrowly triangular, 4–5 mm wide; limb 2-lipped; adaxial lip 2-lobed, lobes triangular-ovate, 4–6 mm long, 7–8 mm wide, with 1 ridge at base of each lobe, ridges purple-red to dark purple-red, densely yellow glandular-puberulent; abaxial lip 3-lobed, lobes oblong, 7–10 mm long, 2.5–5.5 mm wide. Stamens 2, adnate to corolla 5.5–8.8 mm above base, filaments ca. 1 cm long, linear, yellow glandular-puberulent, geniculate below middle; anthers divergent, glabrous. Staminodes 3, linear; lateral ones 4–6 mm long, sparsely yellow glandular-puberulent; middle one 1.0– 1.7 mm long, sparsely glandular-puberulent or glabrous. Disc cricoid, ca. 1 mm high, glabrous, margin entire. Pistil 1.8–2.6 cm long, densely yellow glandular-puberulent; ovary linear, 1.2 mm in diameter; stigma deeply 2-lobed, ca. 1.4 mm wide. Capsule not seen.

Phenology: —Flowering in July and August, fruiting unknown.

Etymology: —The species epithet is derived from the type locality Pingle County, Guilin City, Guangxi, China.

Vernacular name:—平乐报ǝffằ (Chinese pinyin: píng lè bào chūn jù tái).

Taxonomic notes: — Primulina pingleensis is similar to P. pseudoheterotricha in having similar lobes of corolla, cricoid disc and stamens with divergent anthers. It is also close to P. macrodonta in the petiole with similar shape and the broadly cordate or suborbicular leaf blade. However, P. pingleensis is easily distinguished from them by the characters mentioned in the diagnosis above. A detailed comparison among the three species is showed in Table 1 .

Distribution and ecology: — Primulina pingleensis is only found growing in a karst cave in the limestone area of Yuantou Town, Pingle County, Guilin City, Guangxi, China. And the new species is companied by Adiantum gravesii Hance , Asplenium coenobiale Hance , Adiantum malesianum J. Ghatak , Alocasia odora (Roxburgh) K. Koch , Boehmeria nivea (Linnaeus) Gaudichaud-Beaupré , Fallopia multiflora (Thunberg) Haraldson , Pteris deltodon Baker , Pteris vittata Linnaeus , Tectaria devexa (Kunze) Copeland , etc.

Conservation status: —According to Guidelines for Using the IUCN Red List Categories and Criteria ( IUCN 2019), Primulina pingleensis is assessed as Critically Endangered [CR B2ab(ii, iii, V)]. At present, only one population with ca. 460 mature individuals of the new species is known. And its estimated area of occupancy is less than 10 km 2. The main threats come from environmental damages caused by human outdoor activities (such as barbecues or tours) and natural droughts that cause death to some plants. Due to its ornamental value and distribution near the villages, there is also a risk of poaching.

Additional specimens examined (paratype): — CHINA. Guangxi, Guilin City, Pingle County, Yuantou Town , elev. 174 m, 17 July 2021, Ying Qin & Gao Xie GXQY20210717001 ( IBK!) .

Figures

FIGURE 1. Primulina pingleensis. A. Habitat. B. Habit. C. Leaf blade. D. Bracts. E. Cyme. F. Opened corolla. G. Pistil. H. Flower, front view. I. Stamen, side view. J. Flower, top view. K. Flower, side view. L. Stigma. M. Disc. N. Calyx lobe, adaxial view. Photos by Ying Qin.