Boerhavia diffusa
Content
Description
Perennial herb; taproot woody, fusiform, to 1 cm wide. Stem prostrate to decumbent or ascending, to 2 m long, slender, sparsely branched, widely spreading, glabrous or puberulent. Petiole to ca. 4.3 cm long; blade orbicular, rhombic-orbicular or rhombic-ovate on lower part of stem, frequently intergrading to ovate or lanceolate on upper part, 1.1-6 x 0.8-5 cm, apex obtuse to acute, base cuneate, truncate or obtuse, margin sometimes undulate, sub-scalloped or sinuate, and ciliate with multicellular, to 1 mm long hairs, upper surface yellowish-green, glabrous, lower surface paler, glabrous or with puberulent veins. Inflorescence a terminal or axillary, pedunculate, strict or diffusely branched, to 45 cm long panicle, bearing few- to many-flowered subumbellate clusters of subsessile or pedicellate flowers; branches glabrous or glandular-puberulent, bracteolate at base; bracts lanceolate, hyaline; pedicel 0-0.5 mm long; bracteole 0.9-1.7 mm long. Perianth red, purplish-red, maroon or purple, tube closely adherent to ovary, 0.7-1.0 x 0.5 mm, 4-5-ribbed, minutely glandular on ribs, limb broadly campanulate, 5-lobed, sometimes puberulent and ciliate, limb including lobes ca. 1.3 x 0.5 mm, lobes ca. 0.5 mm; stamens 1-3, included to slightly exserted, filaments recurved, united at base; ovary narrowly ellipsoid, ca. 0.5 mm wide, style recurved, stigma slightly exserted, peltate. Anthocarp sessile or subsessile, clavate, narrowly oblanceoloid or subellipsoid, to 4 x 1.5 mm, obtuse, green, 4-5-ribbed, ribs stipitate-glandular, viscous, groove between ribs smooth, with numerouslinear, white raphides appearing as minute streaks; seed narrowly ovoid, ca. 2 mm, castaneous.
Distribution
Guianas present, U.S.A present, pantropical and subtropical present, warm temperate zones such as southern California present
Pantropical and subtropical, sometimes extending to warm temperate zones such as southern California (U.S.A.); 72 collections studied, all from the Guianas (GU: 19; SU: 36; FG: 17).
Notes
Woodson & Schery (1961), in treating this species for the Flora of Panama, observed no tangible taxonomic differences between the two major entities contesting within it for recognition: (1) B. coccinea Mill. (including B. caribaea Jacq. ) of the New World (usually described as having inflorescence-branches puberulent; capitula variously designated as 4-20-flowered (by Nicolson, 1991) or 6-12-flowered (by Kellogg, 1988)); and (2) B. diffusa (including B. paniculata ) of the Old World (inflorescence-branches glabrous, ebracteate; capitula variously designated as 1-5-flowered (by Nicolson, 1991) or 2-4(-7)-flowered (by Kellogg, 1988)), endemic to Sri Lanka and possibly southern India according to Fosberg (1978). The present authors concur with the disposition by Woodson & Schery (1961) of such variation within a single species, B. diffusa . Such opinion is also in accord with that of Bogle (1974), who referred to the "morphologically variable pantropic weed Boerhavia diffusa L. (incl. B. caribaea Jacq. , B. coccinea Mill. , B. decumbens Vahl , B. hirsuta Willd. , B. paniculata Rich. , B. viscosa Lag. & Rodr. )".