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]

PETALONYX

Subshrub; hairs generally rough with whorls of fine barbs
Leaf linear to ± round, entire to toothed; base tapered to cordate
Inflorescence: raceme, generally terminal; bracts 3 per flower, outer 1 > inner 2
Flower: sepals ± deciduous; petals free or claws adherent, fused below blades; stamens generally 5, free; ovary ± ovoid, placenta 1, stigma 1
Fruit: utricle, ± ovoid, generally 5-veined or -ribbed, erect
Seed 1, 1.5–2.5 mm, ± fusiform, generally smooth
Chromosomes: n=23 for all species
Species in genus: 5 species: sw US, nw Mex
Etymology: (Greek: petal claw)
Reference: [Davis & Thompson 1967 Madroño 19:1–32]

Native

P. linearis Greene

Plant 15–100 cm
Leaf generally sessile, 10–25 mm, linear to narrowly (ob)lanceolate, obtuse to acute, entire to irregularly toothed
Inflorescence 4–10 cm; outer bract 5–8 mm, ovate to ± round; inner bracts 3–4 mm, ovate, ± cordate, acute to notched, lobed; pedicels 1–2 mm
Flower: petals 2–5.5 mm, free, white; stamens 3–7 mm, barely exserted; style ± 3–6 mm
Ecology: Sandy or rocky canyons, generally in creosote-bush scrub
Elevation: < 1000 m.
Bioregional distribution: se Mojave Desert, Sonoran Desert
Distribution outside California: sw Arizona, nw Mexico
Flowering time: Mar–May
Horticultural information: TRY.