Boehmeria densiflora var. boninensis, (Nakai) Friis & Wilmot-Dear

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 : 139

b. var. boninensis (Nakai) Friis & Wilmot-Dear , comb. & stat. nov. — Fig. 16 ; Map 18

Basionym: Boehmeria boninensis Nakai (1918) 217; Makino (1925) 1062; Makino & Nemoto (1931) 222. ― Type: Maximowicz 37 (holo TI), Japan, Bonin Islands, July– Aug. 1905.

Stipules up to 10 mm long. Leaves ovate, elliptical or obovate, ± symmetrical, slightly or moderately dimorphic in size and either all leaves of similar shape with broadly acute to obtuse apex, or leaves markedly dimorphic with the ‘larger’ leaves differing in being distinctly attenuate-acuminate; ‘larger’ leaves 10–14(–20) by 4–6(–9) cm, length 2–2.5(–3) × width, marginal teeth rounded or acute, 0.5–1 by (usually) 3.5–4.5 mm; leaves always smooth (never bullate), texture varying from thin-chartaceous with secondary and coarser tertiary veins prominulous abaxially, to coriaceous with even fine reticulation prominent, lateral veins similar on both sides of lamina, basal veins extending just into distal half of lamina, upper veins 1–3 either side arising in distal half. Male inflorescence-bearing axes few-branched near base or unbranched, female unbranched, <10 cm long. Fruiting perianth narrow-ellipsoid or sometimes obovoid, beak conspicuous or very short.

Distribution ― Endemic to Japan (Ryukyu and Bonin Islands).

Habitat & Ecology ― Thickets and sunny rocky clearings, roadsides; 150–910 m altitude.

Conservation status ― See under the species as a whole.

Notes ― See under the species as a whole.

Figures

Map 18 Distribution of Boehmeria densiflora Hook. & Arn. var. boninensis (Nakai) Friis & Wilmot-Dear.

Fig. 16 Boehmeria densiflora var. boninensis (Nakai) Friis & Wilmot-Dear. a. Habit of stem with inflorescence-bearing axes; b, c. detail of stems with di- morphic leaf-pairs of varying form (from different plants); d. leaf, detail of margin and adaxial surface; e. detail of abaxial surface; f. stipules; g. detail of male inflorescence-bearing axis with crowded flower-clusters; h. male bud; i. fruiting perianth (a, d-h: Yoshida & Tannowa s.n., K; b, i: Yasui s.n., TI; c: Tsuiyama s.n., TI). — Scale bars: a-c = 2 cm; d, e = 5 mm; f, g = 2 mm; h, i = 1 mm.