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. crocea Kellogg

Annual, 34–100 cm, erect
Leaves 1–20 cm; basal lobed; cauline toothed or lobed
Inflorescence: bract ovate to obovate, 6–10-toothed
Flower: sepals 7–20 mm; petals 21–36 mm, base with orange spot; stamens 11–28 mm; style 20–30 mm
Fruit 20–35 mm, 3–5 mm wide, straight
Seed 1.5–2 mm, grain-like, minutely papillate
Chromosomes: n=18
Ecology: Rocky slopes, roadsides, grassland, oak/pine woodland
Elevation: < 1500 m.
Bioregional distribution: c&s Sierra Nevada Foothills
Synonyms: M. lindleyi subsp. c. (Kellogg) C. Wolf
Horticultural information: DRN, DRY, SUN: 7, 8, 9, 14, 15, 16, 19, 20, 21; DFCLT.