Boehmeria japonica var. silvestrii, 2013

Wilmot-Dear, C. M. & Friis, I., 2013, The Old World species of Boehmeria (Urticaceae, tribus Boehmerieae). A taxonomic revision, Blumea 58 (2), pp. 85-216 : 191-193

b. var. silvestrii (Pamp.) Friis & Wilmot-Dear , comb. nov. — Fig. 34g –i ; Map 36

Basionym: Boehmeria platanifolia (Maxim.) C.H.Wright var. silvestrii Pamp. (1915) 278. ― Boehmeria silvestrii (Pamp.) W.T. Wang (1982) 204. ― Syntypes: Silvestri 4070 (FI), 4070a (FI), China, Hubei, 1912.

Usually a herb, often much-branched from the base, (rarely a subshrub), to 1.5 m. Stems glabrous or soon glabrescent; hairs sparse, short, fine, adpressed. Leaves broadly rhombic-ovate or ovate-truncate, 4.5–12 by 3–8 cm, length (0.4–)1–1.5 × width; marginal teeth only 8–12 either side; leaf apex deeply laciniate usually to 0.3–0.5 × total lamina length consisting of 1–2 very long subapical teeth either side of terminal tooth and nearly equalling it in length; terminal tooth linear-oblong with 1–several small teeth on each margin and often markedly constricted at its base, subapical teeth often also secondarily toothed; base broadly cuneate or ± truncate; texture membranous or very thin-chartaceous, hairs like the stem or lamina and petiole glabrous. Inflorescence-bearing axes 5–20 cm long, with hairs like the stem, sparse to abundant; fruiting clusters well-spaced or contiguous but not densely congested, individual clusters distinct, 1–4 mm diam. Male tepals without dorsal appendage. Fruiting perianth 1–1.5 by 0.8–1 mm (smallest in small-leaved plants), winged or not.

Distribution ― Northern and central China, South Korea, Japan (Hokkaido, Honshu, Shikoku).

Habitat & Ecology ― Forest margins, streams and moist slopes in deciduous forest; thickets; 100–1400 m altitude (–2600 according to Chen et al. 2003: 173).

Notes ― 1. This variety, like var. tenera , occurs further north in China than var. japonica and is the only variety recorded from Hokkaido. It extends less far into south-eastern China than the other two varieties. Leaves are similar in range of shape to broad and laciniate forms of var. japonica but thin-textured and glabrous or hairs adpressed, leaves also often smaller. Okabe (1956) showed var. silvestrii as sexually reproducing rather than apomictic.

2. The relationships with other varieties and intermediate forms are discussed in detail under the species (see Notes 5–8), and type material here considered as intermediate between the two is cited under var. japonica (see Note 6). A leaf form intermediate with var. japonica is illustrated in Fig. 34j, k .

3 . Boehmeria japonica var. tricuspidata Maxim. is a name not validly published based on a misreading of the account by Maximowicz (1876). It has frequently been used in annotating Japanese material.

Figures

Map 36 Distribution of Boehmeria japonica (L.f.) Miq.var.silvestrii (Pamp.) Friis & Wilmot-Dear.

Fig. 34 a–f: Boehmeria japonica (L.f.) Miq. var. japonica. a. Habit of stem with female inflorescence-bearing axes; b, c. leaves from different plants; d. leaf, detail of adaxial surface; e. leaf, detail of abaxial surface; f. detail of female inflorescence-bearing axis with crowded flower-clusters (inflorescences). — g–i: Boehmeria japonica var. silvestrii (Pamp.) Friis & Wilmot-Dear. g. Leaf; h. leaf, detail of adaxial surface and large tooth near apex; i. leaf, detail of abaxial surface. — j, k: Intermediate between var. japonica and var. silvestrii. j. Leaf; k. leaf, detail of abaxial surface (a, f: Hicken s.n.; b: Suzuki s.n.; c-e: Fortune s.n.; g-i: Liou 4571; j, k: Furuse 21652; all K). — Scale bars: a-c, g, j = 2 cm; d–f, h, i, k = 2 mm.

Fig. 3 Boehmeria didymogyne Wedd. a. Habit; b. large leaf; c. leaf, detail of adaxial surface and margin; d. detail of abaxial surface; e. axillary male flowercluster (inflorescence); f. male flower; g. axillary female inflorescence; h. female perianth and single stigma; i. female perianth and paired stigmas (all: Parish 400; K). — Scale bars: a = 2 cm; b = 1 cm; c, d = 5 mm; e–i = 1 mm.