Boerhavia spicata |
Boerhavia gracillima |
|
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creeping spiderling |
slim-stalk spiderling |
|
Habit | Herbs, annual; taproot tapered, soft or ± woody. | Herbs, perennial, often woody at base; taproot long and ropelike, woody. |
Stems | erect or ascending, sparingly branched throughout, 30–70 dm, densely glandular-villous, or glandular-puberulent, with spreading, nonglandular hairs basally, glabrous 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; larger leaves with petiole 10–30 mm, blade oval, oblong, ovate, or ± triangular, 18–45 × 13–30 mm (distal leaves usually smaller, sometimes longer, proportionately narrower), adaxial surface lightly to densely glandular-pubescent, abaxial surface paler than adaxial, lightly to densely glandular-pubescent, neither surface punctate or both minutely punctate with clusters of brown cells, base truncate, round, or obtuse, margins sinuate, sometimes crisped, apex round to obtuse, rarely acute. |
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 and axillary, branched 1–4 times unequally, with sticky internodal bands; branches strongly ascending, terminating in spicate or racemose flower clusters, axis 10–55 mm. |
axillary or terminal, forked ca. 6–8 times unequally, diffuse, without sticky internodal bands; branches divergent, terminating in 1(–3) flowers. |
Flowers | pedicel 0.4–2.3[–3.7] mm; bracts at base of perianth usually soon deciduous, usually 2, narrowly to broadly lanceolate, 0.7–1.8 mm, apex often acuminate; perianth white to pale pink, campanulate distal to constriction, 1–1.3 mm; stamens (2–)3, slightly exserted or included. |
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 | 5–33 per cluster, usually overlapping or 2–4 in group separated by small gap from next group, straw colored to grayish or reddish tan, broadly obovoid, 1.9–2.4(–2.8) × 1.1–1.3 mm (l/w: 1.7–2.1[–2.3]), apex rounded, glabrous; ribs 5, obtuse-rounded to obtuse, often with low winglike ridge, slightly rugose near sulci; sulci (0.2–)0.5 times as wide as base of ribs, slightly 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. |
2n | = ca. 52. |
|
Boerhavia spicata |
Boerhavia gracillima |
|
Phenology | Flowering late summer–early fall. | Flowering mid summer–late fall. |
Habitat | Sandy or rocky soils in open, arid grasslands, among open shrubs or mesquite and acacia woodlands [tropical deciduous forests] | Dry, usually rocky areas, often along roads, desert scrub, arid grasslands, pinyon-juniper woodlands [tropical deciduous forests] |
Elevation | [100-]700-1800 m ([300-]2300-5900 ft) | [100-]600-2000 m ([300-]2000-6600 ft) |
Distribution |
AZ; NM; TX; Mexico
|
AZ; NM; TX; Mexico
|
Discussion | C. F. Reed (1969) and subsequent authors have included one or more of Boerhavia coulteri, B. torreyana, and B. watsoni as synonymous with B. spicata. Even when those taxa are removed, B. spicata remains a variable species, widespread at low to middle elevations in southwestern North America, and distinguished by its mostly overlapping, obovoid fruits with rather open sulci, and the glandular pubescence on basal parts of the plant. (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. 25. | FNA vol. 4, p. 21. |
Parent taxa | Nyctaginaceae > Boerhavia | Nyctaginaceae > Boerhavia |
Sibling taxa | ||
Synonyms | B. gracillima subsp. decalvata, B. organensis | |
Name authority | Choisy: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 13(2): 456. (1849) | Heimerl: Bot. Jahrb. Syst. 11: 86, plate 2, fig. 1. (1889) |
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