Daphniphyllum calycinum

The species is in section Lunata of Daphniphyllum, along with D. griffithianum and D. majus.[3]

"[T]he premier systematic botanist of the nineteenth century", George Bentham (1800-84), English, described this plant in 1861 in his publication Flora Hongkongensis; a description of the flowering plants and ferns of the island of Hongkong[4][5]

This species grows as a shrub some 1-5-4m tall. The grayish-brown branches are sparsely lenticillate. The petioles are some 4 to 8cm long. The obovate to obovate-elliptic leaf blades are 12-16 by 4-9 cm in size, they are chartaceous, glaucous/hairy and are inconspicuously papillate on lower surface; broadly cuneate leaf base, slightly reflexed margins and obtuse to rounded apex, mucronate; 8-11 pairs of later veins are visible on upper surface, prominent on lower. Male flowers have an 8-10 cm pedicel and a discoid calyx with 3 or 4 broadly triangular lobes, 9 or 10 stamens some 3 mm long with very short filaments, oblong laterally-compressed anthers, connective exserted. Female flowers have a 5-6 mm pedicel, broadly-triangular calyx-loves about 1.5mm in size, ellipsoidal ovary 1.5-2 mm in size, very short style, 2 recurved stigmas. The Infructescence/fruiting head is some 4-5 cm in size, densely arranged with ovoid-ellipsoidal, tubercalate, glaucous drupes some 7 by 4 mm in size, with persistent calyx and style branches. Flowering occurs from April to June, while fruiting is from August to November.[6]

Distinguishing characteristics of this species are: the size (9-16 by 4-9 cm) and shape (obovate to obovate-elliptic) of the leaf blade, the obtuse to rounded apex; and size (about 7 mm), dense arrangement and glaucousness of the fruit.[7]

The plant is native to an area from northern Vietnam to southeastern Zhōngguó/China (Fujian, Guangdong, Guangxi, Hong Kong, south Hunan, south Jiangxi).[2][6]

The shrub grows in forests and thickets at altitudes of occasionally below 100m but mainly 200-700m.[6]

Daphniphyllum calycinum is present on the degraded hillside shrublands of Hong Kong, it is common there in scrubland and forest edges.[8][9] Birds disperse the dry-season fruiting seeds.

The follicular micromycete, or sac-fungi, Mycosphaerella fasciculata, in the Mycosphaerellaceae family, uses this species as a host.[10]

While this species has a very wide distribution with a large population, and it there are no current major or future significant threats identified, like most plant and ecosystems it is a continuing decline in area, extent and/or quality of habitat, and so is of conservation concern.[1]

• vai lá xoan ngược is a name used in Vietnam.[11]
• 牛耳枫, niu er feng, or niu-er-fon, is a name used in Zhōngguó/China[6][12]

The seeds provide abundant oil that was used in lubrication and to make refined soap, however recently because of its toxicity it is only used in biodiesel.[6][12] Roots and leaves are used within Chinese medicine. The plant has many alkaloids and other active ingredients, see for example Wu et al., 2013.[12]