Boerhavia erecta |
Boerhavia gracillima |
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erect boerhavia, erect spiderling |
slim-stalk spiderling |
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Habit | Herbs, annual [slightly woody at base]; taproot tapered, soft or ± woody. | Herbs, perennial, often woody at base; taproot long and ropelike, woody. |
Stems | usually erect, sometimes decumbent, profusely branched primarily distally, 2–12 dm, minutely puberulent with bent hairs basally, usually glabrous, rarely sparsely puberulent distally. |
decumbent to erect, usually profusely branched throughout, 2–15 dm, usually minutely pubescent, rarely glabrous basally, usually glabrous, rarely sparsely and minutely pubescent distally. |
Leaves | 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. |
mostly in basal 1/2 of plant; larger leaves with petiole 3–25 mm, blade broadly rhombic to elliptic-oblong, broadly to narrowly ovate, occasionally wider than long, 18–45 × 13–50 mm (distal leaves smaller, proportionately narrower), adaxial surface glabrous, abaxial surface much paler than adaxial surface, glabrous or with hairs on veins, neither surface punctate, base usually obtuse to round, sometimes shallowly cordate, margins entire or sinuate, often undulate, apex acute, obtuse, or round. |
Inflorescences | 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). |
axillary or terminal, forked ca. 6–8 times unequally, diffuse, without sticky internodal bands; branches divergent, terminating in 1(–3) flowers. |
Flowers | 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. |
pedicel slender, 3–13 mm; bracts at base of perianth quickly deciduous, 2–3, linear-lanceolate to broadly lanceolate, 0.3–1.5 mm, quickly deciduous; perianth wine red to brick red, widely funnelform distal to constriction, 2–4.5 mm; stamens (4–)5(–6), well exserted. |
Fruits | 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. |
usually borne singly, gray-brown to brown, oblong-clavate, 2.8–4.2 × 1–1.5 mm (l/w: [2–]2.2–3.5[–3.8]), apex round to rounded-conic, minutely puberulent, sometimes minutely glandular, rarely glabrous; ribs 5, rounded, smooth or slightly rugose near sulci; sulci 1–2.5 times as wide as base of ribs, not rugose, smooth or minutely papillate. |
Boerhavia erecta |
Boerhavia gracillima |
|
Phenology | Flowering early summer-mid fall. | Flowering mid summer–late fall. |
Habitat | Disturbed areas, gardens, road and railroad rights-of-way, stream beds | Dry, usually rocky areas, often along roads, desert scrub, arid grasslands, pinyon-juniper woodlands [tropical deciduous forests] |
Elevation | 0-1700 m [probably much higher in tropics] (0-5600 ft [probably much higher in tropics]) | [100-]600-2000 m ([300-]2000-6600 ft) |
Distribution |
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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AZ; NM; TX; Mexico
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Discussion | 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.) |
The phase Boerhavia gracillima subsp. decalvata from low elevations in the Big Bend region of Texas and adjacent Mexico differs from the remainder of B. gracillima in that it is usually erect or strongly ascending, has glabrous fruits, and has flowers with purple to brick red perianths; the flowers are also in the upper half of the size range for the species. It is highly local and completely intergradient with surrounding populations of B. gracillima in the strict sense. In fruit and flower features the phase resembles B. anisophylla; in its diffuse inflorescence with slender branches (0.15 mm diam. proximal to the flower versus 0.25 mm in B. anisophylla) and in its deciduous bracts it is more similar to B. gracillima. Some populations of B. gracillima also have glabrous fruits, and a local endemic in Durango, B. chrysantha Barneby, differs primarily in its yellow perianths similar in size to those of B. gracillima subsp. decalvata. The complex is in need of careful study. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 4, p. 22. | FNA vol. 4, p. 21. |
Parent taxa | Nyctaginaceae > Boerhavia | Nyctaginaceae > Boerhavia |
Sibling taxa | ||
Synonyms | B. gracillima subsp. decalvata, B. organensis | |
Name authority | Linnaeus: Sp. Pl. 1: 3. (1753) | Heimerl: Bot. Jahrb. Syst. 11: 86, plate 2, fig. 1. (1889) |
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