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. affinis Greene

Annual, 5–47 cm, erect
Leaves 1–17 cm; basal toothed or lobed; cauline entire to lobed
Inflorescence: bract lanceolate to obovate, entire or toothed
Flower: sepals 2–7 mm; petals 3–10 mm, base with orange spot, tip rounded, notched, or toothed; stamens < 6.5 mm; style 3–6.5 mm
Fruit 12–28 mm, 1–3 mm wide, straight or arched < 90°
Seed 1–2 mm, ± 1 mm wide, prism-like, smooth; angles grooved; sides ± flat
Ecology: Sandy grassland, woodland, creosote-bush scrub
Elevation: < 1200 m.
Bioregional distribution: s Sierra Nevada, San Joaquin Valley, se San Francisco Bay Area (Mount Hamilton), Inner South Coast Ranges, Transverse Ranges, San Jacinto Mountains, Desert
Distribution outside California: Arizona, Baja California
Flowering time: Apr–May
Horticultural information: DRN, DRY, SUN: 2, 7, 9, 10, 11, 12, 14, 15, 16, 18, 19, 20, 21, 22, 23, 24; DFCLT.