LOASACEAE

LOASA FAMILY

Barry Prigge

Annual to shrub; hairs needle-like, stinging, or rough
Leaves alternate in CA, generally ± pinnately lobed; stipules 0
Inflorescence various
Flower bisexual, radial; sepals generally 5, generally persistent in fruit; petals generally 5, free or fused to each other or to filament tube; stamens 5–many, filaments thread-like to flat, sometimes fused at base or in clusters; petal-like staminodes sometimes present; pistil 1, ovary inferior, chamber generally 1, placentas generally 3, parietal, style 1
Fruit: generally capsule (utricle)
Seeds 1–many
Genera in family: 15 genera, ± 200 species: especially Am (Africa, Pacific)
Reference: [Ernst & Thompson 1963 J Arnold Arbor 44:138–142]

MENTZELIA

BLAZING STAR

Annual to shrub; hairs generally barbed-rough (smooth)
Leaf linear to ovate, generally ± lobed; basal in rosettes, generally petioled; cauline generally sessile, ± reduced upward
Inflorescence: generally cyme (or flower 1); bract generally 1 per flower, generally green
Flower: sepals lanceolate to deltate, generally persistent; petals 5, free, generally yellow; stamens generally many, ± free, generally unequal, inner filaments generally thread-like; staminodes 0 or 5–many, outer often petal-like; ovary generally cylindric, placentas generally 3, style thread-like, stigma 3-furrowed or -lobed
Fruit generally tapered to base, sometimes curved
Seeds generally many, grain- to prism-like (triangular in X -section), angled, or lenticular and winged (important to identification)
Species in genus: ± 50 species: w US, ± tropical Am
Reference: [Darlington 1934 Ann Missouri Bot Garden 21:103–226]

Native

M. laevicaulis (Hook.) Torr. & A. Gray

Perennial 22–100 cm
Stem erect, branching above middle
Leaves generally lobed; basal 19–24 cm; cauline 2–10 cm
Inflorescence: bract linear to lanceolate, entire, toothed at base to deeply 4–5-lobed
Flower: sepals 15–46 mm; petals 30–80 mm; stamens 15–55 mm, outer filaments < 2 mm wide; style 2.5–7 mm
Fruit 15–44 mm, 8–13 mm wide, straight
Seed 3–4 mm, 2–2.5 mm wide, lenticular, winged, fine-pebbled
Chromosomes: n=11
Ecology: Sandy to rocky slopes, washes, roadcuts
Elevation: < 2700 m.
Bioregional distribution: California (except Great Central Valley, Sonoran Desert)
Distribution outside California: to British Columbia, Montana, Wyoming, Nevada
Flowering time: Jun–Oct
Horticultural information: DRN, DRY, SUN: 1, 2, 3, 7, 9, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24; DFCLT.