Bergera unifolia C.L.Deng & F.J.Mou

Mou, Feng-Juan, Hu, Xiu, Ha, Bui Thu & Cuong, Nguyen Manh, 2023, Taxonomic revision of Bergera J. Koenig ex L. (Rutaceae) based on the molecular phylogeny and morphology, European Journal of Taxonomy 860, pp. 141-180 : 173-174

Bergera unifolia C.L.Deng & F.J.Mou

Fig. 14

Bergera unifolia C.L.Deng & F.J.Mou, Annales Botanici Fennici 58 (4–6): 363 ( Deng et al. 2021). – Type: CHINA • Guangxi, Guilin (transplanted from Duyang, Dahua); alt. ca 540 m; 18 Aug. 2017; F. J. Mou 595; holotype: SWFC!; isotype: SWFC !.

Etymology

The specific epithet refers to the unifoliate leaves.

Material examined

CHINA • Guangxi, Dahua ; 18 Aug. 2017; C.L. Deng et al. 1, 2, 3; preserved in Guangxi Academy of Specialty Crops, China .

Description

Shrub, up to 1 m high. Spineless, glabrous; oil glands prominent and easily visible principally on the young branches, rachis, and petiolule, as well as along the margins and in the mesophyll. Young branches are green, becoming grey-brown when old. Leaves are unifoliolate; rachis ca 2.5–5.5 cm long and swelling at the base; petiolule more swollen than rachis and 4–5 mm long; leaflets subcoriaceous, shining above and hairy underneath, and elliptical or oblong-lanceolate; leaf blades 7–12 cm long, 3–6 cm wide, acute cuneiform at the base, narrowed attenuate and slightly emarginate at the tip, and obtuse or subemarginate, serrate; with 10–15 pairs of lateral veins and clearly distinct from the veinlets and elevated above the surface below. Cymes are both axillary and terminal and up to 50-flowered. Flower buds are small, 2.5–3.5 × 2.0 mm; calyxes 5-lobed, short, ovate, acute, and 0.8–1.3 × 0.5–0.9 mm; petals oblong, 2.5–3.5 × 0.5–1.0 mm wide; pellucid dots on the surface of the petals and calyx lobes. Stamen filaments are free, 10, alternately unequal in length, ciliate, 2.5 mm and 3 mm long, respectively, dilated at the base and abruptly pointed at the tip; anthers not large, pubescent. Pistils are 1.8–2.5 mm long; ovaries are oblong, yellow, substipitate, and glandular, borne on a low disc, with 2 ovules, each with 1 ovule; styles cylindrical, pubescent, and white. Fruits are fleshy, red, oval, and up to 15 mm long.

Phenology

Flowering between May and June, while fruiting from July to August.

Distribution and habitat

The species is only endemic to Dahua (Guangxi Province, China). It grows in limestone hills at alt. 500 m.

Remarks

This species is similar to B. stenocarpa with unifoliate leaves, but is distinguished easily from the latter by having smaller and thinner leaflets. The leaflets of this taxon are also close to B. kwangsiensis due to the hairs under the leaflets, oil glands and smell ( Deng et al. 2021).

Figures

Fig. 14. Bergera unifolia C.L.Deng & F.J.Mou. A. Inflorescence. B. Fruit. C–D. Dorsal side of leaf. E. Flower. F. Flower parts. Photos taken by Feng-Juan Mou in China.