Primulina liangwaniae B.M.Wang & Y.H.Tong, 2023

Tong, Yi-Hua, Ni, Jing-Bo & Wang, Bing-Mou, 2023, Primulina liangwaniae (Gesneriaceae), a new species from Guangdong, China, Phytotaxa 630 (2), pp. 154-158 : 155-157

Primulina liangwaniae B.M.Wang & Y.H.Tong , sp. nov. ( Fig. 1 ).

Type: — CHINA. Guangdong Province: cultivated in South China Botanical Garden, introduced from Yingde City, Huanghua Town, limestone hills, on rocks in shaded places, elev. ca. 528 m, 21 March 2022 (fl.), Y.H. Tong, J.B. Ni, B.M. Wang & J. Cai TYH-2568 (holotype IBSC , isotype IBK) .

Diagnosis: —Being close to P. versicolor in having similar shape and color of corollas, but it mainly differs in the smaller (5.4–9.5 × 4.5–7 cm vs. 8–18 × 6.5–16.5 cm) leaf blades with a crenate (vs. entire) margin, much shorter peduncles (2–4 cm vs. 8–18 cm), smaller bracts (2.2–2.8 × 1.5–2.2 cm vs. 5–5.5 × 4.4–5 cm) with margin being crenate on upper part and entire on lower part (vs. entire thoroughly), much shorter pedicels (4–7 mm vs. 10–22 mm) and narrowly cordate (vs. forked) stigma.

Description: —Perennial herbs, rhizomes short, ca. 1.5 cm long, ca. 8 mm in diam. Leaves all basal, opposite; petiole cross section sub-semicircular, 1–3 cm long, 2–3 mm thick, together with leaf blade and peduncle densely white- or purplish-villous and pubescent, base broadened; blade thickly carnose, dark green or tinged purplish adaxially, green tinged purplish, purplish or purple abaxially, ovate or broadly ovate, 5.4–9.5 × 4.5–7 cm, apex obtuse or subacute, base cuneate or truncate, sometimes slightly cordate, margin crenate, lateral veins 4–6 pairs, impressed adaxially, raised abaxially. Cymes axillary, unbranched or with 1–2 branches, (2–)4–9-flowered; peduncles light green, 2–4 cm long, 2–2.5 mm thick; bracts 2, opposite, greenish, tinged purple at apex, concave, ovate or broadly ovate, 2.2–2.8 × 1.5–2.2 cm, margin crenate on upper part, entire on lower part, apex acute, outside densely white- or purplish-villous and pubescent, inside glabrous. Pedicels 4–7 mm long, densely puberulent. Calyx 5-parted nearly to the base, lobes linear, 9–10 × ca. 2 mm, margin entire or with 1–3 inconspicuous teeth each side, puberulent on both sides. Corolla yellowish or yellowish white, with three patches at the sinuses of the two upper lip lobes, patches purple outside and dark purple inside, sometimes absent outside and yellow inside, and with 2 purple bands on the two sutures of the middle lobe of the lower lip to the position where fertile stamens inserted and 9 dark purple stripes, 3.2–4 cm long, outside densely glandular-pubescent and puberulent, inside glabrous on tube and densely glandular-pubescent on lobes; tube infundibuliform, 2.6–2.8 cm long, ca. 1.2 cm in diameter at the mouth; limb distinctly 2-lipped, adaxial lip 2-lobed to over half the length, lobes ovate, round at apex, 5–6 × ca. 9 mm; abaxial lip 3-lobed, lobes oblong with the central one smaller, round at apex, 8–12 × 6–7 mm. Stamens 2, adnate to ca. 1.3 cm above the base of the corolla tube, filaments white, base inflated, ca. 1 cm long, geniculate below the middle, densely glandular-pubescent throughout; anthers elliptic, ca. 4 mm long; staminodes 3, lateral ones tinged purple at apex, adnate to ca. 1.2 cm above the base of corolla tube, 5–6 mm long, densely glandular-pubescent, apex bended, the central one very small, adnate to ca. 2.5 mm above the base of corolla tube, ca. 0.5 mm long, glabrous. Disc annular, ca. 1 mm high, glabrous. Pistil ca. 3.1 cm long; ovary ca. 1.3 cm long, densely white-villous and pubescent; style ca. 1.5 cm long, densely glandular-pubescent or puberulous; stigma narrowly cordate, 2.5–3 mm long, shallowly lobed, lobes ca. 0.5 mm long. Capsule pale green, linear, 4–6.5 cm × 2–3.5 mm, with persistent calyx lobes at base and style at apex, densely white-villous and pubescent, persistent calyx lobes 11–13 × 2–2.5 mm. Seeds small, sub-turbinate, 0.3–0.4 × 0.1–0.15 mm.

Distribution and ecology: — Primulina liangwaniae is only known from the type locality in Huanghua Town of Yingde City, China. It grows on limestone rocks at an elevation of ca. 530 m. The associated species include some plants also adapted to limestone, such as Begonia leprosa Hance , Pilea peltata Hance , Nephrolepis cordifolia (L.) C.Presl, Selaginella spp. , etc.

Phenology: —Flowering in late March to early April; fruiting in May.

Etymology: —The specific epithet is derived from the name of the third author’s mother, Ms. Liang-Wan Zhang, who encouraged her son to maintain continuous enthusiasm with plants, but sadly passed away in 2020. The Chinese name is given as “ ̊șẫǝüë ”.

Provisional conservation status: —We only found one small population with ca. 50 individuals growing on limestone rocks of the entrance of a cave at the type locality. Due to lack of time and inconvenient traffic, a thorough population assessment of this species in that limestone area has not been made, so it is best classified as ‘Data Deficient’ (DD) at present ( IUCN Standards and Petitions Committee 2022).

Additional specimens examined (paratype): — CHINA. Guangdong Province: cultivated in South China Botanical Garden, introduced from Yingde City, Huanghua Town, limestone hills, on rocks in shaded places, elev. ca. 528 m, 22 May 2022 (fr.), Y.H. Tong, J.B. Ni, B.M. Wang & J. Cai TYH-2569 (IBSC).

Discussion: — Primulina liangwaniae has high ornamental values due to its adorable and relatively small habit and beautiful flowers. This species and its close relative, P. versicolor , are both distributed in the same county, i.e., Yingde, but in different towns, viz. Huanghua Town and Xiniu Town, and their type localities are not far (ca. 30 km) from each other. Besides of the differences mentioned in the diagnosis section, a more detailed comparison between the two species is provided in Table 1 . It is worth mentioning that their flowering times are also different: this new species flowers from late March to early April, while P. versicolor flowers from late June to early July ( Pan et al. 2016). Except these two species, there are also other four sympatrically distributed congeneric species, viz. P. yingdeensis Z.L.Ning, M.Kang & X.Y.Zhuang in Ning et al. (2016: 401), P. qingyuanensis Z.L.Ning & M.Kang in Ning et al. (2013: 48), P. alutacea F.Wen, B.Pan & B.M.Wang in Pan et al. (2016: 30) and P. lobulata (W.T. Wang 1982: 55) Mich.Möller & A.Weber in Weber et al. (2011: 783), as well as some gesneriads of other genera, e.g., Petrocodon dealbatus Hance (1883: 167) and Hemiboea follicularis C.B.Clarke in Hooker (1888: t. 1798), which indicates that this limestone area harbours a relatively high biodiversity of gesneriads. It is believed that more new species will be discovered if botanical investigations are continuously conducted in the future.

Figures

FIGURE 1. Primulina liangwaniae. A. Habitat; B. Flowering plant, top view; C. Flowering plant, side view; D. Inflorescence, front view; E. Inflorescence, side view; F. Opened corolla; G. Stamens; H. Disc, part of ovary and three calyx lobes; I. Stigma and part of style; J. Capsule with persistent calyx. Photographed by Yi-Hua Tong.