Boerhavia diffusa |
Boerhavia torreyana |
|
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red spiderling, spreading hogweed |
creeping spiderling |
|
Habit | Herbs, perennial [rarely appearing annual], sometimes slightly woody at base; taproot fusiform, woody. | Herbs, annual; taproot tapered, soft or ± woody. |
Stems | decumbent, ascending, or erect, usually profusely branched throughout, 3–10 dm, glabrous or minutely pubescent basally, glabrous or sparsely pubescent distally. |
prostrate or decumbent-ascending, usually profusely branched throughout, 10–80 dm, minutely puberulent with flat hairs, usually also with spreading hairs, sometimes also glandular basally, glabrous distally. |
Leaves | mostly in basal 1/2 of plant; larger leaves with petiole 10–30 mm, blade broadly lanceolate, ovate, or broadly ovate, occasionally ± round, 20–60 × 15–50 mm (distal leaves smaller, often proportionally narrower), base truncate, broadly cuneate, round, or shallowly cordate, often oblique, margins sinuate, apex obtuse to round, abaxial surface paler than adaxial, glabrous or minutely puberulent, sometimes glandular, usually with few large multicellular hairs on veins, adaxial surface glabrous, rarely sparsely puberulent, neither surface punctate. |
mostly in basal 1/2; larger leaves with petiole 7–20 mm, blade oblong-ovate, oval, ovate, or lanceolate, 20–45 × 9–25 mm (distal leaves usually shorter, proportionately narrower), adaxial surface glabrous or sparsely and minutely puberulent, abaxial surface paler than adaxial, glabrous or minutely puberulent, sometimes glandular, neither surface punctate or both punctate with minute clusters of brown cells, base truncate, rounded, or obtuse, margins sinuate to sinuate-crisped, apex round to obtuse or acute. |
Inflorescences | terminal, forked ca. 3–6 times ± equally, diffuse, occasionally with sticky internodal bands; branches divergent, terminating in compact subumbellate or capitate, 2–5-flowered clusters. |
terminal and axillary, forked ca. 3–6 times unequally, diffuse, usually with sticky internodal bands; branches strongly ascending, terminating in spicate or racemose flower clusters, axis 10–40 mm. |
Flowers | pedicel shorter than 0.5 mm; bract at base of perianth quickly deciduous, 1, lanceolate, 0.8–1 mm; perianth purplish red to reddish pink or nearly white, campanulate beyond constriction, 1–1.5 mm; stamens 2–3, included or barely exserted. |
pedicel 0.1–1.7 mm; bract at base of perianth usually soon deciduous, usually 1, broadly lanceolate to lance-attenuate, 0.5–1.2 mm; perianth whitish to purplish pink, campanulate distal to constriction, 1–1.3 mm; stamens 2, slightly exserted. |
Fruits | (1–)2–5(–9) per cluster, gray-brown to brown, obpyramidal, (3–)3.5–4.5 × 1–1.2 mm (l/w: 2.8–4.1), apex broadly conic, with sparse or moderately dense stipitate-glandular hairs on ribs, less densely pubescent or glabrous in sulci [rarely entirely glabrous]; ribs 5, round, smooth; sulci ± 2–2.5 times as wide as base of ribs, not rugose, not papillate. |
2–12 per cluster, usually remotely spaced, sometimes about 1/2 overlapped, occasionally ± paired, straw colored to grayish tan, narrowly obovoid, 2.2–3(–3.8) × 0.9–1.1 (–1.3) mm (l/w: [1.9–]2.2–3.1), apex round or round-obtuse, glabrous; ribs 5, obtuse or round-obtuse, strongly rugose near sulci; sulci 0.5–1 times as wide as base of ribs, not or slightly rugose, papillate. |
2n | = 26, 52, 54, 116. |
= 52. |
Boerhavia diffusa |
Boerhavia torreyana |
|
Phenology | Flowering mid winter–early fall [year-round]. | Flowering mid summer and early fall. |
Habitat | Disturbed areas, waste places, roadsides, dry pinelands, among scrub on tropical reefs | Sandy or rocky soils in deserts or arid grasslands |
Elevation | 0-50[-1800] m (0-200[-5900] ft) | 600-1300 m (2000-4300 ft) |
Distribution |
FL; GA; SC; Mexico; Central America; South America; West Indies; Asia; Africa; Indian Ocean Islands; Pacific Islands; Australia
|
AZ; NM; TX; UT; Mexico (Chihuahua, Coahuila) [South America (introduced in Argentina)]
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Discussion | Boerhavia diffusa belongs to a pantropical complex whose distribution, because of differing taxonomic treatments, is not precisely discernable. In North America, the West Indies, and elsewhere, the complex has been treated as having one (e.g., R. W. Long and O. Lakela 1971; R. P. Wunderlin 1998) or two species (E. A. Kellogg 1988; J. K. Small 1913c; P. C. Standley 1918; C. Whitehouse 1996). In the latter situation various binomials have been used. The abrupt bend in the ribs near the fruit apex, making a broadly conic apex, seems to be a useful character for distinguishing most B. diffusa. The shape of the apex, the sparse pubescence of the fruit, the few fruits in individual terminal clusters, and the open, ± leafless inflorescence may have led R. E. Woodson Jr. and H. J. Kidd (1961) to suspect hybridization of this complex with the annual B. erecta. Hybridization is plausible (R. Spellenberg 2000), but clearly intermediate plants are not known. The leaves are sometimes used as a vegetable (C. Whitehouse 1996). Extracts from roots are used to prepare an expectorant, a diuretic, and a laxative, and in treating asthma (S. P. Ambasta 1986). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boerhavia torreyana occurs in the Chihuahuan Desert, extends north of the Mogollon Rim in arid sites, and barely enters southeastern Arizona. The slender, remotely flowered inflorescences and the papillate sulci distinguish this from other spicate species. There were fewer ants and aphids on plants of B. torreyana (reported as B. spicata) with intact internodal bands as compared to those whose bands had been experimentally altered (Y. McClelan and W. J. Boecklen 1993). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 19. | FNA vol. 4, p. 26. |
Parent taxa | Nyctaginaceae > Boerhavia | Nyctaginaceae > Boerhavia |
Sibling taxa | ||
Synonyms | B. spicata var. torreyana | |
Name authority | Linnaeus: Sp. Pl. 1: 3. (1753) | (S. Watson) Standley: Contr. U.S. Natl. Herb. 12: 385. (1909) |
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