Boerhavia diffusa |
Nyctaginaceae |
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red spiderling, spreading hogweed |
four-o' clock family |
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Habit | Herbs, perennial [rarely appearing annual], sometimes slightly woody at base; taproot fusiform, woody. | Herbs, shrubs [or trees], annual or perennial. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Roots | fibrous to fleshy or tuberous. |
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Stems | decumbent, ascending, or erect, usually profusely branched throughout, 3–10 dm, glabrous or minutely pubescent basally, glabrous or sparsely pubescent distally. |
procumbent to erect, sometimes clambering through other plants. |
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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. |
opposite [rarely alternate], exstipulate, sessile or petiolate, pairs equal or unequal; blade linear to ovate or ± round, thin to thick and fleshy or succulent, plane or undulate, base ± symmetric to strongly unequal, margins entire or sinuate, glabrous or pubescent. |
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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 or lateral in leaf axils, usually cymose or racemose, open or congested, bracteate; bracts distinct or connate, sometimes forming an involucre containing 1–80 flowers, when containing only 1 flower, calyxlike, sometimes brightly colored. |
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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. |
unisexual or bisexual, sometimes cleistogamous, incomplete, showy or inconspicuous; calyx usually 5 connate sepals, varying from small and not showy to large, notably petaloid, and colorful, corollalike; corolla absent; stamens commonly as many as calyx lobes and alternate with them, varying 1–18[–30]; filaments connate basally [or distinct]; gynoecium 1-carpellate; styles filiform; stigmas capitate, fusiform to linear, or ending in tufts of hairs; ovule 1; placentation basal. |
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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. |
aerial (hypogeous in Okenia), accessory, radially symmetric or dorsiventrally compressed anthocarps, consisting of achene or utricle enclosed in fleshy, leathery, or woody base of calyx, sides longitudinally 5- or 10-ribbed or not ribbed, glandular or not, smooth, wrinkled, or warty, glabrous or pubescent; ribs, when present, varying from fine and linear to broad and obtuse ridges, or thick to thin wings, or rows of curved gland-tipped teeth. |
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Seed | 1; seed coat membranaceous; embryo straight or curved; cotyledons foliaceous; endosperm scanty; perisperm abundant. |
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x | = 9 or 10? |
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2n | = 26, 52, 54, 116. |
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Boerhavia diffusa |
Nyctaginaceae |
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Phenology | Flowering mid winter–early fall [year-round]. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Habitat | Disturbed areas, waste places, roadsides, dry pinelands, among scrub on tropical reefs | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Elevation | 0-50[-1800] m (0-200[-5900] ft) | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
FL; GA; SC; Mexico; Central America; South America; West Indies; Asia; Africa; Indian Ocean Islands; Pacific Islands; Australia
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Primarily tropical and subtropical regions worldwide |
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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.) |
Genera 30, species 300 (13 genera, 88 species in the flora). Fruits of Acleisanthes, Allionia, most Anulocaulis, Boerhavia, Cyphomeris, and many of Mirabilis produce mucilage when wetted. Several genera are pantropical (e.g., Boerhavia, Commicarpus, Pisonia); Mirabilis jalapa, a popular ornamental, has escaped in temperate and subtropical regions of the world. Only five genera, Boerhavia, Commicarpus, Mirabilis, Phaeoptilum, and Pisonia, are indigenous to the Old World, and of these only Phaeoptilum does not occur in the New World. Mirabilis is represented in the New World by almost 60 indigenous species, whereas only one species is indigenous to the Old World. The greatest generic diversity is perhaps in the arid regions of southern North America. Boerhavia also shows considerable diversity in Australia; Commicarpus is particularly diverse in Africa and the Middle East; most Bougainvillea species are Brazilian. Overall, there is little economic importance to the family. Mirabilis jalapa and a few species of Bougainvillea and hybrids are popular ornamentals. Others supply leaves that can be used as a vegetable and compounds that have medicinal use. Bougainvillea glabra Choisy, a native of South America, is a woody, scandent plant grown on walls and trellises, with brilliant red-purple, orange, yellowish, or white bracts providing spectacular color. It may persist about old dwellings, and occasionally in plant dumps and gardens in warmer parts of the flora area, but it has apparently not naturalized. Classification at the generic and suprageneric levels is problematic in Nyctaginaceae. Two great students of the family recognized differing numbers of tribes: A. Heimerl (1934c) five worldwide, and P. C. Standley (1918) six in North America alone. J. Hutchinson (1959) recognized eight tribes worldwide. Many genera are small, and G. H. M. Lawrence (1951) noted that 50% of the genera are monotypic. P. C. Standley, particularly in his earlier works (1911, 1918), recognized segregate genera, especially from widespread and variable genera such as Mirabilis and Pisonia as those are treated here. Whereas there has been a tendency among recent authors to accept a widely inclusive genus concept for Mirabilis (A. L. Bogle 1974), the segregate genera from an inclusive Boerhavia have been mostly retained (e.g., C. F. Reed 1969), although this view has not been completely accepted (F. R. Fosberg 1978). Nyctaginaceae is believed to have been derived from Phytolaccaceae or a close common ancestor (A. Cronquist 1981), a relationship supported by J. Rodman et al. (1984) and S. R. Downie and J. Palmer (1994). Considerable anatomical work has increased our understanding of unique structural attributes in the family, and also often of its position within the Caryophyllales (e.g., H.-D. Behnke 1972, sieve-tube plastids; E. Balfour 1965, anomalous nature of secondary wood; J. W. Nowicke 1970 and J. W. Nowicke and T. J. Luikart 1971, pollen morphology; A. D. Joshi and V. S. Rao 1934, vascular anatomy of perianth). As A. L. Bogle (1974) discussed, the term “anthocarp,” traditionally applied to the accessory fruit, has been defined in several ways and is an ambiguous term. Technically the fruit is a diclesium, as defined by A. E. Radford et al. (1974). This term has not been applied in descriptions of taxa in the family, and for these reasons the general term “fruit,” as used in the descriptions of taxa that follow, refers to the accessory fruit of this family. The side walls of the diclesium may bear sticky stipitate glands that are involved in dispersal by animals. The surfaces of diclesia in other genera may be more or less warty, and when so, secrete mucilage of unknown function when wetted. In other genera the ribs of the diclesia are expanded as hyaline wings, or the diclesium bears long winglike folds, both probably adaptations that enhance dispersal by wind. Chromosome numbers and their significance are poorly understood in the family, and many species are estimated to have fairly high numbers. Chromosomes are small and in meiosis often tend to clump. Reported chromosome numbers range, without any obvious pattern, from 2n = 20 to 2n = 136. V. Bittrich and U. Kühn (1993) suggested that polyploidy and aneuploidy have played a significant role in the evolution of species, and that there is no clear relationship to the presumed x = 9 of the Centrospermae. For most genera, x (base number) is unknown. Pollen grains in the Nyctaginaceae are 3- to 18-colpate, or 12- or more porate. A broad survey of pollen morphology (J. W. Nowicke 1970; J. W. Nowicke and T. J. Luikart 1971) supported A. Heimerl’s (1934c) tribal and subtribal delimitation, but because of relative uniformity it was not useful in aiding with generic delimitation within the large subtribe Nyctagininae. R. A. Levin (2000) has demonstrated that molecular methods are successful in elucidating phylogeny within the family; her work examining relationships in Acleisanthes and Selinocarpus supports monophyly of Mirabilis, and raises some question about sectional classification in that genus. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4, p. 19. | FNA vol. 4, p. 14. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | Nyctaginaceae > Boerhavia | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Name authority | Linnaeus: Sp. Pl. 1: 3. (1753) | Jussieu | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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