Boehmeria rotundifolia var. scabrella, 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 : 170-171

l. var. scabrella (Roxb.) Friis & Wilmot-Dear , comb. nov. — Fig. 24j–o ; Map 29

Basionym: Urtica scabrella Roxb. , Flora Indica, vol. 3 (1832) 581. ― Boehmeria macrophylla Hornem.var. scabrella (Roxb.) D.G. Long (1982) 129. ― Boehmeria platyphylla D.Don var. scabrella (Roxb.) Wedd. (1856) 365. ― Syntypes: Wallich 4581A (K-WALL), India, Assam,Goalpara; Wallich 4581B (K-WALL;isosyn G, M), Bangladesh,Silhet; Wallich 4581C (K-WALL), Nepal; Wallich 4581D (K-WALL),cultivated in Hort.Bot.Calcutta.– See Note 1.

Urtica caudata Burm.f. (1768) 197, non Poir. (1798) 640, nec Blume (1825) 492. ― Boehmeria caudata (Burm.f.) J.J.Sm. (1910) 706, nom. illeg., non Sw. (1788) 34. ― Type: Unknown collector (not traced), Indonesia, Jawa [Java]. – See Note 2.

Urtica caudata Blume (1825) 492, nom. illeg., non Burm.f. (1768) 197, nec Poir. (1798) 640. ― Type: Unknown collector (not traced), Indonesia, Jawa [Java], Tjanjor. – See Note 2.

Woody-based herb, to 1 m tall. Stem with very sparse to dense hairs only 0.3–0.4 mm long, these fine or coarse, ± uniform, usually stiff and straight, closely-adpressed or half-adpressed, sometimes (only where long and dense) slightly curved. Stipules often conspicuous, up to 11 mm long. Leaves ovate and often markedly asymmetrical with outline of two sides and length of basal veins dissimilar; usually small or medium, 5–10(–13) by 3–7(–10) cm, relatively broad, length 1.2–1.5(–1.8) × width; acumen short and broad consisting mainly of a single tooth (with 1–2 teeth in its lower third or half); base broad-cuneate, broadly rounded, to markedly obliquely truncate or subcordate; marginal teeth numerous, (30–)35–45 either side, small close-spaced distinctly up-curved, 1.5–2 by 2(–3) mm, relatively narrow with width 1–1.3(–1.5) × length; texture (thin-) or thick-chartaceous, leaves often rugose, adaxial surface with adpressed or half-adpressed hairs like those on stem (but usually longer, up to 0.7 mm), stiff giving rough texture; abaxial surface with hairs stiff but shorter ± spreading; petiole usually relatively short relative to lamina, 0.25–0.4(–0.7) × length. Inflorescence-bearing axes short only 2–8(–12) cm long, ± erect (female sometimes pendent at tip), male axes with lateral branches throughout length which are shorter than or equalling its main axis, female axes unbranched or with short side branches 1–3 cm long near base bearing male clusters, also very occasionally its main axis with a tuft of leaves at tip; female clusters crowded sometimes ± contiguous along parts of axis, especially on shorter axes. Fruiting perianth not widely varying, mostly ovoid to ellipsoid with minute abrupt beak, moderately laterally flattened with or without distinct marginal rim.

Distribution ― Eastern and western Himalaya: northern India, Nepal; southern China, Indonesia (west of Wallace’s line: Jawa, Bali, Borneo).

Habitat & Ecology ― Shaded places in forest, scrub and disturbed old cultivations; 200–2400 m altitude.

Conservation status ― Least Concern (LC). Approximately 100 collections clearly referable to this variety have been seen. Its locations in forest along the Himalayas and the extension of these mountains into southern China, are probably not currently at risk, although it is not clear whether the open and often somewhat disturbed habitats elsewhere in which it is also found are currently threatened.

Notes ― 1. In 1832 Roxburgh refers to his Urtica scabrella as “native of Chittagong” [ Bangladesh] without citing any collections; his Catalogue (1814: 67) lists living material from Chittagong (donated by a “ Mr J. R. ”) and Wallich 4581D may represent this plant although it bears no further information and all four specimens under K­WALL 4581 bear Roxburgh’s name. Weddell (who cites Wallich 4581 without qualification) does not mention Sylhet but only ’Assam and?Nepal’ so had perhaps not seen 4581B .

2. Var. scabrella is the only taxon within B. macrophylla Hornem. s.lat. known from Jawa. In spite of missing type material of Urtica caudata Burm. f. the taxon is placed here based on later material from Jawa, as was implied by Friis & Marais (1982: 163). Urtica caudata Blume , nom. illeg., is also placed here on the authority of Weddell (1856: 365) who referred it to B. platyphylla D.Don var. scabrella (Roxb.) Wedd.

3. As discussed (see Note 5-x under the species as a whole), var. scabrella is distinctive its combination of short ± erect inflorescence-bearing axes, the male ones much-branched, the female axes with congested clusters, and small or medium leaves, usually rough-hairy with numerous close- spaced teeth, often thick-textured and/or asymmetrical. It is partly sympatric to var. macrostachya (which occurs in much of the Indian subcontinent), and a range of material exists intermediate in leaf and/or inflorescence-morphology with either var. macrostachya or var. rotundifolia . In Jawa occur also forms with leaf shape (but not indumentum) approaching var. sumatrana .

4. Var. scabrella is one of only two varieties of subsp. macrophylla partly sympatric with subsp. virgata ( var. virgata west of Wallace’s line in Jawa and Bali) but, as discussed in detail under the species, the two entities are morphologically very distinct with no intermediate forms nor possibility of confusion.

5. Var. scabrella has been confused frequently with the sympatric but more widespread B. pilosiuscula and sometimes also with B. polystachya and B. clidemioides (see detailed discussed (Notes 3, 4, 7) under the subspecies).

Figures

Map 29 Distribution of Boehmeria virgata (G.Forst.) Guillem.subsp.macro­ phylla (Hornem.) Friis & Wilmot-Dear var.scaberrima (Roxb.) Friis & Wilmot- Dear (●), B. virgata (G.Forst.) Guillem. subsp.macrophylla (Hornem.) Friis & Wilmot-Dear var.sumatrana (Miq.) Friis & Wilmot-Dear (▲) and intermediates between B. virgata subsp. macrophylla var.scaberrima and B. virgata subsp. macrophylla var. macrostachya (ä).

Fig. 24 a–i: Boehmeria virgata subsp. macrophylla var. macrostachya (Wight) Friis & Wilmot-Dear. a. Habit of stem with inflorescence-bearing axes; b. leaf, detail of adaxial surface;c. leaf, detail of abaxial surface;d. detail of stem and stipules;e. detail of male inflorescence-bearing axis and flower-clusters (inflorescences); f. male bud; g. detail of female inflorescence-bearing axis and flower-cluster (inflorescence); h, i. fruiting perianths of different form (from different plants). — j–o: Boehmeria virgata subsp. macrophylla var. scabrella (Roxb.) Friis & Wilmot-Dear. j. Habit of stem with branched inflorescence-bearing axes; k. leaf; l. leaf,detail of adaxial surface; m. leaf, detail of abaxial surface;n. detail of stem and stipules; o. fruiting perianth. — p: Boehmeria virgata subsp. macrophylla var. canescens (Wedd.) Friis & Wilmot-Dear. Leaf, detail of adaxial surface (a–c, h: Gamble 9034; d, i: Haines 5068; e, f: Haines 2309; g: Clarke 34129; j: Schiffner 1900; k, n: Hooker & Thompson s.n.; l, m, o: Ford 173; p: Wallich 4582; all K). — Scale bars: a, j, k = 2 cm; b-d, l-n = 2 mm; e-h, i, o = 1 mm.