NYCTAGINACEAE

FOUR O'CLOCK FAMILY

Richard Spellenberg

Perennial, shrub, tree, glabrous or hairy
Stem often forked
Leaves opposite, sessile or petioled, pairs generally unequal; blade generally entire
Inflorescence generally forked; of spikes, clusters, or umbels, each unit sometimes with a calyx-like involucre
Flower bisexual, radial; perianth of 1 whorl, petal-like, bell- to trumpet-shaped, base hardened, tightly surrounding ovary in fruit, lobes 4–5, generally notched to ± bilateral; stamens 1–many; ovary superior (appearing inferior because of hardened perianth base), style 1
Fruit: achene or nut, smooth, wrinkled, or ribbed
Genera in family: 30 genera, 300 species: warm regions, especially Am; some ornamental (Bougainvillea ; Mirabilis , four o'clock).

ABRONIA

SAND VERBENA

Annual, perennial herb, generally glandular
Stem prostrate to ascending, generally ± red
Leaf generally fleshy, petioled
Inflorescence: head or umbel; flowers opening together or outer first; receptacle conic, ± smooth
Flower: perianth salverform to trumpet-shaped, generally fragrant, lobes 4–5; stamens 4–5, included; stigma linear, included
Fruit: body fusiform; lobe-like wings (0)2–5 (if present, prominent, opaque, thick, not continuous above fruit body)
Species in genus: 25 species: w North America
Etymology: (Greek: graceful)
[Galloway 1975 Brittonia 27:328–347] Closely related to Tripterocalyx.

Native

A. gracilis Benth.

Annual, glandular-hairy
Stem prostrate, < 1 m
Leaf: petiole 10–35 mm; blade 20–45 cm, thin, oblong or elliptic, edges scalloped or wavy
Inflorescence: peduncle 2–10 cm; bracts 6–10 mm, ovate; flowers 13–24
Flower: perianth tube 6–17 mm, ± white or pink, limb 7–16 mm wide, light magenta to purplish red
Fruit 6–11 mm, glandular-hairy; wings 5, thin, broadly rounded, extending above top of fruit body, base of floral tube not forming a prominent hard beak at top of fruit body
Ecology: Sandy soil
Elevation: < 500 m.
Bioregional distribution: South Coast (San Diego Co.), s Sonoran Desert
Distribution outside California: nw Mexico
Intergrades with A. umbellata , A. villosa
Horticultural information: sand, DRN, DRY, SUN: 24.