Boerhavia triquetra |
Boerhavia erecta |
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creeping sticky stem, slender spiderling |
erect boerhavia, erect spiderling |
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Habit | Herbs, annual; taproot tapered, soft or ± woody. | Herbs, annual [slightly woody at base]; taproot tapered, soft or ± woody. |
Stems | erect or ascending, occasionally decumbent, moderately or profusely branched, primarily distally, 1–5 dm, minutely puberulent with bent hairs basally, glabrous or minutely puberulent distally. |
usually erect, sometimes decumbent, profusely branched primarily distally, 2–12 dm, minutely puberulent with bent hairs basally, usually glabrous, rarely sparsely puberulent distally. |
Leaves | mostly in basal 1/2 of plant; larger leaves with petiole 4–8[–15] mm, blade broadly ovate or oval to lanceolate, 10–21[–35] × 6–8[–13] mm (distal leaves smaller, proportionately narrower), adaxial surface usually glabrous, rarely minutely puberulent, abaxial surface paler than adaxial, glabrous, neither surface punctate, base round [obtuse], margins shallowly sinuate, apex acute, obtuse, or round. |
mostly in basal 1/2 of plant; larger leaves with petiole 6–40(–55) mm, blade broadly rhombic-ovate, triangular-ovate, ovate, oval, or lanceolate, 20–50(–80) × 10–45 mm (distal leaves smaller, proportionately narrower), adaxial surface usually glabrous, sometimes minutely puberulent, usually minutely punctate, abaxial surface slightly paler than adaxial, usually glabrous, sometimes minutely puberulent, usually punctate with small patches of small brown cells, base obtuse to round, margins entire or sinuate, apex usually acute, less often obtuse or rounded. |
Inflorescences | terminal or axillary, forked ca. 3–6 times ± evenly (or clearly unevenly), diffuse, with sticky internodal bands; branches usually terminating in umbels or flowers borne singly, usually well beyond leaves. |
terminal, forked ca. 4–6 times ± evenly, diffuse, usually with sticky internodal bands; branches strongly ascending, terminating in irregular umbellate or subracemose clusters of flowers, not all pedicels attaching at same point (flowers occasionally borne singly). |
Flowers | pedicel 0.3–4.5 mm; bracts at base of perianth quickly deciduous, 2, linear-lanceolate to lanceolate [ovate], 0.5–0.6 mm; perianth whitish to pale pink or purplish, campanulate beyond constriction, 1 mm; stamens 2–3, included or barely exserted. |
pedicel (0–)0.3–2.5(–5) mm; bracts at base of perianth deciduous, usually 2, narrowly to broadly lanceolate, 0.5–1 mm, apex often acuminate; perianth whitish, usually tinged with pink or purple [bright pink] between lobes and in tube, campanulate beyond constriction, 1–1.5 mm; stamens 2–4, slightly exserted. |
Fruits | 1–7 per umbel, straw colored or gray-brown, obpyramidal, 2.5–3.1 × 1.3–1.9 mm (l/w: 1.6–2.1), base stipelike, apex round-truncate, glabrous; ribs 3–4(–5), acute or winglike, tapering to pedicel, slightly rugose or undulate near sulci; sulci 0.5–1 times as wide as base of ribs, coarsely transversely rugose, smooth or very faintly papillate. |
1–11 per cluster, pale greenish to straw colored or tan, narrowly obconic, (2.7–)3–3.5[–4] × 1.2–1.5 mm (l/w: (2–)2.3–3.2), apex truncate or broadly low conic, glabrous; ribs 5, acute, slightly rugose adjacent to sulci; sulci 0.5–1 times as wide as base of ribs, slightly to prominently coarsely transverse rugose, not papillate. |
Boerhavia triquetra |
Boerhavia erecta |
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Phenology | Flowering summer–late fall. | Flowering early summer-mid fall. |
Habitat | Sandy or gravelly areas in deserts | Disturbed areas, gardens, road and railroad rights-of-way, stream beds |
Elevation | [0-]100-300 m ([0-]300-1000 ft) | 0-1700 m [probably much higher in tropics] (0-5600 ft [probably much higher in tropics]) |
Distribution |
AZ; CA; Mexico (Baja California, Baja California Sur, Sonora)
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AL; AR; AZ; FL; GA; LA; MD; MO; MS; NC; NM; OK; SC; TN; TX; Mexico; Central America; South America; West Indies [Widely introduced throughout the tropics and warm-temperate regions]
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Discussion | Boerhavia triquetra, very narrowly defined here by a predominance of 3- and 4-ribbed fruits, is uncommon in the flora, known to occur only on low deserts near the Colorado River and southward around the Sea of Cortez. The species has few- or 1-flowered terminal inflorescences. Its relationship to, and distinctness from, B. intermedia, needs clarification. In the area of the type locality, Bahia de los Angeles, on the east coast of Baja California, some plants have only 3- and 4-winged fruits, whereas most will have 3-, 4-, and some 5-winged fruits. The five-winged fruits do not differ from those of B. intermedia, a species common on the peninsula. Intergradient plants occur on the peninsula and on islands in the gulf. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Boerhavia erecta occasionally forms mixed populations with B. intermedia without apparent intergradation. Rarely, some specimens seem to combine features of either species, particularly with regard to inflorescence structure. This is especially so in Sonora, Mexico, and in parts of the Sonoran Desert in Arizona. The two species bloom simultaneously and are visited by small insects. Given the presumed close relationship and weedy habitats of each, hybridization seems possible. Usually, the two species can be distinguished by the differences in fruit length, the appearance of a crownlike apex of the nearly mature fruits of B. erecta (apex of ridges slightly expanded, apex of fruit slightly conic), and the more precisely constructed terminal umbels of B. intermedia. Both species, particularly B. intermedia, may produce entire inflorescences with branches terminating in single flowers. R. E. Woodson Jr. and H. J. Kidd (1961) suggested that B. erecta hybridizes with the perennial B. diffusa. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 24. | FNA vol. 4, p. 22. |
Parent taxa | Nyctaginaceae > Boerhavia | Nyctaginaceae > Boerhavia |
Sibling taxa | ||
Name authority | S. Watson: Proc. Amer. Acad. Arts 24: 69. (1889) | Linnaeus: Sp. Pl. 1: 3. (1753) |
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