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).

MIRABILIS

FOUR O'CLOCK

Perennial, subshrub
Stem repeatedly forked, decumbent to erect
Leaf generally petioled
Inflorescence forked; calyx-like involucres densely clustered or solitary in axils, bell- to saucer-shaped; flowers 1–16 per involucre, blooming sequentially
Flower: perianth funnel- to bell-shaped, lobes 5; stamens 3–5, generally exserted; stigma ± spheric, generally exserted
Fruit ± round to club-shaped, smooth to 5-ribbed; wing 0
Species in genus: ± 60 species: Am, Himalayas
Etymology: (Latin: wonderful)
Fls open in evening, close in morning. Spp. intergrade; Hermidium , Oxybaphus sometimes segregated, but intergrade with other species; careful study needed. [Pilz 1978 Madroño 25:113–132]

Native

M. bigelovii A. Gray

Stem ascending to erect, < 8 dm, generally glandular-hairy
Leaf: blade 1–4 cm, ovate to ± reniform, glandular-hairy
Inflorescence: involucres clustered near ends of branches, bell-shaped; bracts 5, 5–6 mm, > 1/2 fused, lobes ovate; flower 1 per involucre
Flower: perianth 8–12 mm, widely funnel-shaped, white to pale pink (especially in w part of range)
Fruit ± 3 mm, ± spheric to ovoid, lightly dotted or wrinkled, glabrous
Ecology: Rocky places
Elevation: < 2300 m.
Bioregional distribution: White and Inyo Mountains, Desert
Distribution outside California: to Utah, Arizona, nw Mexico
Varieties intergrade, especially in e D. Poorly distinguished morphologically and geographically from M. californica; these may prove to be infraspecific entities in a more broadly conceived species
Recent taxonomic note: Mirabilis laevis (Benth.) Curran var. villosa (Kellogg) Spellenb.

Native

var. retrorsa (A. Heller) Munz

Stem scabrous above with short, reflexed hairs, often also ± glandular
Flower: perianth white to pale pink
Fruit ± spheric, with ± prominent pale lines
Ecology: Habitat of sp.
Elevation: < 2300 m.
Bioregional distribution: White and Inyo Mountains, Desert
Distribution outside California: to Utah, Arizona, nw Mexico
Flowering time: Mar–Jun
Horticultural information: DRN, DRY, SUN: 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
Recent taxonomic note: Mirabilis laevis (Benth.) Curran var. retrorsa (A. Heller) Jeps.