Walsura guangxiensis Y.Nong & Y.F. Huang, 2023

Nong, You, Xu, Chuan-Gui, Wei, Gui-Yuan, Yan, Ke-Jian, Qu, Xin-Cheng, Zhang, Zhan-Jiang, Hu, Ren-Chuan & Huang, Yun-Feng, 2023, Walsura guangxiensis (Meliaceae), a new species from Guangxi, China, PhytoKeys 234, pp. 219-227 : 219

Walsura guangxiensis Y.Nong & Y.F. Huang sp. nov.

Figs 1 , 2 Chinese name: guǎng xī gē shé shù (广西割舌树)

Diagnosis.

Walsura guangxiensis is readily distinguishable from the other two Chinese species of Walsura , Walsura guangxiensis is similar to W. pinnata and W. robusta regarding secondary veins 3-9 (vs. secondary veins 8-11 / secondary veins 5-8); but differs with petals being pale yellow (vs. petals white / petals white); stamen filaments undivided, connate into tubes above the middle (vs. stamen filaments broad, basal to middle part connate into a tube, tip 2-lobed / stamen filament base or basal to middle part connate into a tube); berry oval, 1-2 cm long and 1-1.2 cm wide, glabrous, thin peel, yellow and shiny when mature (vs. berry globose to ovoid, ca. 1.5 cm in diam., densely covered with yellowish gray trichomes / berry globose to ovoid, 1-2 cm in diam., densely covered with yellowish gray trichomes).

Holotype.

China. Guangxi: Fengshan, 24°24'29.02"N, 106°50'23"E, alt. 866 m, in subtropical evergreen broad-leaved forest, limestone, 7 June 2022, R.C. Hu, HRC210424001 (holotype: GXMI!; isotypes:IBK! GXMI!).

Description.

Trees 3-5 m tall. Branches grey-brown, glabrous or sometimes young branches yellow pubescent or glabrescent, with grey-white lenticels. Leaves 10-26 cm; petioles (1.5) 3-7 cm; with fine hairs. Leaflets 3 or 5, subsessile, papery or thinly leathery, elliptic or oblong-lanceolate, tapering at the apex, descending at the base or cuneate or broadly cuneate, glabrous on both sides, 3-9 pairs of lateral veins, obvious protrusions on both sides of reticular veins and entire edges of leaflet blades; lateral leaflets are 3-14 cm long and 1.5-5 cm wide and the apical leaflets are larger. Petiole 2-5 mm long, terminal up to 1 cm, glabrous. Panicle axillary or terminal, with cyme-like branches, shorter leaves, appressed yellow pubescence, with total pedicels, small pedicels 1-3 mm long, jointed at the lower part and puberulent, 3 triangular bracteoles at the base, pubescence. Calyx short, 4- or 5-lobed, lobes ovate, apex acute, puberulent or glabrous. Petals 4 or 5, pale yellow, puberulent outside; elliptical, much longer than sepals, free, imbricate in bud. Stamen filament tube 8-10 split; filaments are tapered at the top, undivided, connate into tubes above the middle, with short bristles on the upper part of the inner surface and anthers 8-11, yellow and oval, inserted at the top of filaments. Disc cup-shaped, fleshy. Ovary glabrous, 1-loculed, with 2 ovules in each locule, as long as or slightly longer than the ovary. Style cylindrical; stigma globose, tip not divergent. Berry is oval, stipitate, 1-2 cm long and 1-1.2 cm wide, glabrous, 1 loculed, with 1 or 2 seeds, thin peel, yellow and shiny when mature.

Phenology.

Flowering in April-May; fruiting in June-August.

Etymology.

Guangxi is located in the southwest of China and is a biodiversity hotspot where many new species or new species records have been found ( Hu et al. 2019; Luo et al. 2020; Feng et al. 2021; Xin et al. 2021; Huang et al. 2022). The new species, W. guangxiensis , is found in this region and is named after the geographic location.

Distribution and habit.

Known only from the southwest of Guangxi, China. The new species mainly occurs at elevations of 800 m and is usually found together with Cinnamomum saxatile H. W. Li, Myrsine kwangsiensis (E. Walker) Pipoly & C. Chen, Platycarya strobilacea Sieb. et Zucc., Wrightia sikkimensis Gamble. It often grows in stone crevices with barren soil.

IUCN Red List Category.

Data available for the new species are still insufficient to assess its conservation status. According to the IUCN Criteria ( IUCN 2022), it is considered Data Deficient (DD) until more information becomes available. Although W. guangxiensis currently has relatively good growth and protection status, further collection and monitoring are necessary to allow more conclusive estimations about the rarity and vulnerability of the species. Therefore, special attention should be given to the conservation of the new species of Walsura .

Additional specimen.

Tiane. Southwest Guangxi: limestone hills, fl. 8 May 2020, C.G. Xu, XCG20200508001 (GXMI!);Lingyun. Yuntai Park, fr. 7 June 2013, GXMI063377 (GXMI!); Lingyun. Yuntai Mountain, fr. 12 August 2013, GXMI063363 (GXMI!)

Notes.

This new species is represented by eight individuals that have been found so far in the wild, three of which were fruiting and used for species description.

Figures

Figure 1. Line drawing of Walsura guangxiensis A flowering branch B flowers C fruits D style and ovary E staminal tube spread out F free portion of stamen (Drawn by Xin-Cheng Qu).

Figure 2. Walsura guangxiensis A flowering branch B flowers C staminal filaments D staminal tube E calyx F ovary and stigma G flower and stipules H fruits (Photographed by You Nong and Ke-Jian Yan, edited by Yuan Fang).