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erect boerhavia, erect spiderling

fivewing spiderling

Habit Herbs, annual [slightly woody at base]; taproot tapered, soft or ± woody. Herbs, annual; taproot tapered, soft or ± 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.

usually erect or ascending, occasionally decumbent, moderately or profusely branched primarily distally, 2–6 (–8) dm, minutely puberulent with bent hairs basally, glabrous or minutely puberulent 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 7–25 mm, blade broadly ovate or oval to lanceolate, 20–45 × 7–16 mm (distal leaves smaller, sometimes longer, proportionately narrower), adaxial surface usually glabrous, occasionally glandular-puberulent, often minutely punctate, abaxial surface paler than adaxial, glabrous or glabrate, usually punctate with small patches of reddish or brownish cells, base round, obtuse, or truncate, margins entire or slightly sinuate, 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).

terminal, forked ca. 3–6 times ± evenly (or clearly unevenly), diffuse, usually with sticky internodal bands;

branches strongly ascending, terminating in umbels or flowers borne singly, occasionally subumbellate (all pedicels not attaching at same point), rarely irregularly compound umbels.

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 0.5–3.2 mm;

bracts at base of perianth quickly deciduous, (1–)2, narrowly lance-acuminate, 0.5–1 mm;

perianth whitish to pale pink or purplish, campanulate distal to constriction, 0.7–1.2[–2] mm;

stamens 2–3, included or barely 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.

1–15 per cluster, straw colored or gray-brown, obconic, broadly low conic, 2–2.8(–3.2) × 0.7–1.3 mm (l/w: 1.7–3.2), apex nearly truncate, glabrous;

ribs (4–)5, acute, slightly rugose or undulate near sulci;

sulci 0.2–1 times as wide as base of ribs, coarsely transversely rugose, smooth or very faintly papillate.

2n

= 52, ca. 54.

Boerhavia erecta

Boerhavia intermedia

Phenology Flowering early summer-mid fall. Flowering summer–late fall.
Habitat Disturbed areas, gardens, road and railroad rights-of-way, stream beds Sandy or gravelly areas in deserts and arid grasslands, disturbed areas
Elevation 0-1700 m [probably much higher in tropics] (0-5600 ft [probably much higher in tropics]) [0-]100-1700 m ([0-]300-5600 ft)
Distribution
from FNA
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]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NM; NV; TX; Mexico (Baja California, Baja California Sur, Chihuahua, Coahuila, Durango, Sonora)
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.)

Boerhavia intermedia is a wide-ranging and variable species of the arid areas of southwestern North America. Ordinarily, the terminal inflorescence is an umbel of at least a few flowers. Plants with few-flowered umbels often have only one flower at some of the terminal inflorescences. Plants with predominantly or entirely one-flowered terminal inflorescences occasionally occur in the eastern part of the range. To the west, and especially on the Coloradan portion of the Sonoran Desert and on the Baja California peninsula, plants with one-flowered terminal inflorescences are more frequent, and even though those have five-ribbed fruits, they often have been identified as B. triquetra. In that region, such plants may have proportionately broader fruits as the ribs become more winglike. Some plants in southern California bear a few fruits with four angles, and in this respect are intermediate to B. triquetra.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 4, p. 22. FNA vol. 4, p. 23.
Parent taxa Nyctaginaceae > Boerhavia Nyctaginaceae > Boerhavia
Sibling taxa
B. anisophylla, B. ciliata, B. coccinea, B. coulteri, B. diffusa, B. gracillima, B. intermedia, B. linearifolia, B. megaptera, B. pterocarpa, B. purpurascens, B. spicata, B. torreyana, B. triquetra, B. wrightii
B. anisophylla, B. ciliata, B. coccinea, B. coulteri, B. diffusa, B. erecta, B. gracillima, B. linearifolia, B. megaptera, B. pterocarpa, B. purpurascens, B. spicata, B. torreyana, B. triquetra, B. wrightii
Synonyms B. erecta var. intermedia
Name authority Linnaeus: Sp. Pl. 1: 3. (1753) M. E. Jones: Contr. W. Bot. 10: 41, unnumbered fig. at end of is sue. (1902)
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