Actinostephanus F.Wen, Y.G.Wei & L.F.Fu, 2022

Wen, Fang, Xin, Zi-Bing, Hong, Xin, Cai, Lei, Chen, Xiao-Yun, Liang, Jun-Jie, Wang, Hui-Feng, Maciejewski, Stephen, Wei, Yi-Gang & Fu, Long-Fei, 2022, Actinostephanus (Gesneriaceae), a new genus and species from Guangdong, South China, PhytoKeys 193, pp. 89-106 : 89

Actinostephanus F.Wen, Y.G.Wei & L.F.Fu gen. nov.

Diagnosis.

Actinostephanus F.Wen, Y.G.Wei & L.F.Fu resembles two small genera, Boeica C.B.Clarke and Leptoboea Benth. according to the molecular evidence and some morphological data, but differs from the latter two by the following distinguishing characters: leaves in whorls of three, all closely clustered at the top; corolla bowl-shaped, 5-lobed, actinomorphic; capsule hard, oblong-ovoid, short, 3-4 mm long, densely appressed villous, wrapped by persistent densely pubescent calyx lobes, style persistent. The detailed distinguishing characters of this new genus and its congeners are listed in Table 1 .

Type and only known species.

Actinostephanus enpingensis F.Wen, Y.G.Wei & Z.B.Xin, sp. nov.

Description.

Herbs, perennial, acaulescent, or forming elongated rhizome slightly fleshy growing after some years, rhizomes cylindrical, surface densely brown pubescent, fibrous root filiform, forming adventitious buds and plantlets in the middle or at the end of the fibrous root. Leaves all basal, whorls of three, sometimes opposite, all closely clustered at the top, forming a rosette, or clustered forming a rosette at the top of the rhizome after years of growth. Leaf-blades obovate elliptic, asymmetric, rarely symmetric, attenuate to base and base usually oblique, rarely aequilateral. Bracts 2. Calyx actinomorphic, 5-parted to the base. Corolla actinomorphic, bowl-shaped; tube very short, shallow bowl-shaped; limb quinquelobate, lobes equal. Stamens 4, separated, anthers dorsifixed, free, dehiscing longitudinally. Disc glabrous, margin crenulate. Ovary conical, stigma punctate. Capsule oblong-ovoid, appressed villous, wrapped by persistent calyx lobes, and the abaxial surfaces of calyx lobes covered densely pubescent. The number of seeds per capsule fewer. Seeds bigger, elliptic, both ends pointed.

Etymology.

The genus name, " Actinostephanus ", consists of two parts, both derived from the Greek. The front part, " Actino -" is derived from ἀκτῑ ́ς (aktῑ́s, "ray, beam"), means radiating; the latter half, "- stephanus ", is derived from Στέφανος ( Stéphanos, “crown”), is also closely associated in ᾰ ̓́νθος ( ánthos, "flower, blossom, bloom"), hints corolla. The combined Greek word-roots characterize the uncommon corolla characteristic of the new genus and species. The character of the corolla, in China’s Gesneriaceae, is rare. Only three species belonging to two genera were known to have actinoform corolla in China, namely Bournea sinensis Oliv., B. leiophylla (W.T.Wang) W.T.Wang & K.Y.Pan ex W.T.Wang and Oreocharis esquirolii H. Lév. before this new genus was discovered.

Vernacular name of the new genus.

Chinese mandarin: Fú Guàn Jù Tái Shǔ (辐冠苣苔属).

Distribution and habitat.

Endemic to Enping county, Guangdong province, China, under evergreen broadleaved forests in a montane mountain yellow soil area at 170-250 m altitude.