Fenghwaia gardeniicarpa G.T. Wang & R.J. Wang, 2021

Wang, Gang-Tao, Shu, Jiang-Ping, Jiang, Guo-Bin, Chen, Yu-Qiang & Wang, Rui-Jiang, 2021, Morphology and molecules support the new monotypic genus Fenghwaia (Rhamnaceae) from south China, PhytoKeys 171, pp. 25-35 : 25

Fenghwaia gardeniicarpa G.T. Wang & R.J. Wang sp. nov. Fig. 2

Type.

China. Guangdong Province, Jiangmen City, Taishan, Mt. Nanfengshan, under secondary mixed forests, 22°11'N, 112°56'E, elev. ca. 410 m, 6 July 2019, R.J. Wang, G.T. Wang & G.B. Jiang 1228 (holotype: IBSC0849961; isotypes: CSH0171170; IBK00421260; IBSC0849962; IBSC0849963; KUN1347949; PE02251842).

Description.

Treelet, evergreen, 0.5-2 m tall, slender, much branched at top; main stems dark or brown, slender, glabrous; young branches rusty strigose at surface. Leaves alternate, anisophyllous, often clustering at the top of branches; petiole 2-5 mm long, pubescent; leaf blade 5.5-10.1 × 1.9-4.0 cm, elliptic, oblanceolate-elliptic or ovate, thinly leathery, glabrous both sides, acuminate to caudate at apex, cuneate at base; secondary veins 3-5 each side, mid-rib and secondary veins smooth adaxially and prominent abaxially; margin entire at base and then serrate to apex. Inflorescence in sessile or shortly peduncled, axillary cymes or small thyrses, 3-5-flowered; bracts ca. 0.5-1.0 mm long, lanceolate to broadly triangular, yellow to rusty. Flowers bisexual, actinomorphic, yellowish-green, ca. 4-5 mm in diameter; pedicels very short to 4-6 mm long, glabrous; calyx lobes five, 2.0-3.0 × ca. 1.5 mm, ovate triangular, depressed longitudinally at middle; hypanthium 2-3 mm long, slightly campanulate; petals five, ca. 1.5 mm long, cucullate, each partly covering the pollen-presenting surface of the anthers, shortly clawed at base, concaved at apex; stamens five, antepetalous, ca. 1.3 mm long, enclosed by petals; anthers ca. 0.3 mm long, ovoid, 4-locular, dorsifixed, filaments ca. 1.0 mm long; disc inconspicuous, adnate to the lower part of hypanthium; styles ca. 1.5 mm long, stigma 3-lobed; ovary inferior, 3-1ocular, with one ovule in each locule, ovules anatropous, basal, erect. Fruit drupaceous, more or less fleshy, cylindrical, ca. 1.5 cm long, 0.4-0.6 cm in diam., with five longitudinal ridges on surface, slowly dehiscent at top and then septicidally, glabrous; calyx lobes persistent. Seeds ca. 4 × 3 mm, orbicular, dorsiventrally compressed, brown, verrucose at surface, with an elongate and pronounced basal appendage.

Phenology.

Flowering from June to October; fruiting from August to December.

Palynology.

The pollen grains of the new species are monads, isopolar, suboblate, radially symmetrical, angulaperturate, 3-zono-colporate apertures and psilate to perforate tectum. The pollen size is 14.9 (13.3-17.1) × 21.5 (16.1-21.1) μm and P/E value is 0.86 (Fig. 3 ).

Distribution and habitat.

Fenghwaia gardeniicarpa is endemic to mountains in Jiangmen District, Guangdong Province, China. It grows under secondary mixed forests at altitudes of 230-450 m, mountain slopes with 60-70% canopy density, accompanying herbal Gahnia tristis Nees ( Cyperaceae ) and Adiantum flabellulatum L. ( Adiantaceae ) and woody Barthea barthei (Hance ex Benth.) Krasser ( Melastomataceae ), Dunnia sinensis Tutcher ( Rubiaceae ) and Illicium dunnianum Tutcher ( Schisandraceae ).

Preliminary conservation assessment.

About 2000 mature Fenghwaia gardeniicarpa individuals from four localities have been found in less than 800 km2 up to now. This area can be classified as the extent of occurrence. The plants have no any ornamental or medicinal uses. They are well protected in a Nature Reserve and the population is not severely fragmented. In addition, no population decline and no extreme fluctuations caused by natural events have been observed in their habitats. According to the International Union for Conservation of Nature (2012) and IUCN Standards and Petitions Committee (2019), a category of Near Threatened (NT) is recommended for Fenghwaia gardeniicarpa for the present.

Etymology.

The species name highlights the striking resemblance with fruits of Gardenia jasminoides Ellis ( Rubiaceae ), an unusual and new feature for a fruit of Rhamnaceae .

Vernacular name.

Feng Huai Mu (Chinese pronunciation); 封怀木 (Chinese name).

Paratypes.

China: Guangdong Province, Jiangmen City, Taishan, Chixi Town, Tonggu Village, 21°55'N, 112°56'E, elev. 440 m, 2 June 2019, Y.Q. Chen & G.T. Wang 1223, 1224, 1225, 1226 (IBSC!); Guangdong Province, Jiangmen City, Taishan, Chixi Town, Luobo Village, 21°55'N, 112°55'E, elev. 107 m, 20 June 2020, R.J. Wang & Y.Y. Liu 5928 (IBSC!); Guangdong Province, Jiangmen City, Xinhui, Gudoushan Nature Reserve, 22°9'N, 112°55'E, elev. 231 m, 3 October 2019, H.G. Ye et al. GDS-00849 (IBSC!).

Figures

Figure 2. Fenghwaia gardeniicarpa: A main stem with glabrous surface B young stem with pubescent surface C fertile branches D adaxial (left) and abaxial (right) side of leaf blade, respectively E serrated leaf margin F stipule G inflorescence H flower in anthesis I morphology of petals and stamens J longitudinal section of a flower, showing the stamens enclosed by cucullate petals K young fruit L transection section of an ovary, showing three ovules M mature fruit N transection section of mature fruit with only one well-developed seed O dehiscent capsule P seed, with an elongate and pronounced basal appendage. Photos: G. T. Wang, G. B. Jiang.

Figure 3. Pollen grains of Fenghwaia gardeniicarpa: A polar view B equatorial view.