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. oblongifolia (A. Gray) Heimerl

Stem branched near top, ascending to erect, 1–5 dm; glabrous or strigose
Leaf: blade < 4 cm, narrowly 3-angled, ± finely hairy
Inflorescence broadly forked; involucre cup-shaped, glandular-hairy, enlarged and papery in fruit; bracts 5, ± 8 mm in fruit, 1/2–2/3 fused; flowers 5 per involucre
Flower: perianth 10–12 mm, broadly funnel-shaped, magenta
Fruit 3–5 mm, club-shaped, finely warty between the 5, wide, wrinkled or warty ribs
Ecology: Dry, rocky areas
Elevation: 1500–2500 m.
Bioregional distribution: Desert Mountains (Ivanpah, New York mtns)
Distribution outside California: to Colorado, Texas, n Mexico
Flowering time: May–Jun
Synonyms: Oxybaphus comatus (Small) Weath
Variable complex, with many named forms; in need of critical study. CA plants have ± narrow leaves and branch ± at base (like M. linearis var. decipiens (Standley) Welsh of s Rocky Mtns). Exc for distribution of hairs, CA plants also resemble M. pumila from DMtns. The concept for both these taxa in CA is tentative and is likely to change
Horticultural information: TRY.