Leaves generally basal and cauline, alternate, generally simple; stipules 0
Inflorescence: generally raceme
Flower bisexual; sepals 4, free; petals (0)4, free, generally white or yellow, often clawed; stamens generally (2,4)6, generally 4 long, 2 short; ovary 1, superior, chambers generally 2, septum membranous, connecting 2 parietal placentas, style 1, stigma simple or 2-lobed
Fruit: generally capsule ("silique") with 2 deciduous valves, sometimes breaking transversely or indehiscent
Seeds 1–many per chamber
Genera in family: 300+ genera, 3000+ species: worldwide, especially cool regions; some cultivated for food (especially Brassica, Raphanus ) and ornamental
Recent taxonomic note: Recently treated to include Capparaceae [Rodman et al. 1993 Ann Missouri Bot Gard 80:686–699; Rollins 1993 Cruciferae of Continental North America. Stanford Univ Press]
Family description, key to genera by Robert A. Price.
ARABIS
ROCK CRESS
Biennial, perennial herb; base woody or not; hairs 0 to dense, simple, forked, stellate, or multibranched; caudex branched or not
Stem branched or not, cylindric, leafy
Leaves: basal petioled, entire or dentate; cauline generally sessile, entire or dentate, base often lobed, often clasping stem
Inflorescence: bracts 0
Flower erect to reflexed; sepals erect; petals spoon-shaped to oblong and narrowed at base or narrowly obovate, white to deep purple, rarely straw-colored
Fruit erect to reflexed, linear, straight to curved, flat parallel to septum, rarely ± cylindric
Seeds ± many, generally 1 row per chamber, flat or plump, winged or not; embryonic root at edges of both cotyledons
Species in genus: ± 120 species: temp North America, Eurasia, Africa
Etymology: (Latin: of Arabia)
| Native |
A. sparsiflora Torr. & A. Gray
Perennial; caudex branched or not; hairs multibranched to simple, spreading or appressed, coarse
Stems 1–several, simple or branched above, 3–9 dm, generally stout; hairs below, sometimes above
Leaves: basal many, 3–10 cm, linear-oblanceolate to wider, entire or ± dentate, hairy, tip acute; cauline many, sessile, 2–8 cm, linear-lanceolate or wider, base lobed, generally sagittate, clasping stem
Flower: petals 9–12 mm, 2–4 mm wide, spoon-shaped, pink to purple
Fruit ascending to recurved, 6–12 cm, straight or curved, glabrous; pedicel ascending to spreading-recurved, 5–15 mm, often stout, glabrous to hairy
Seed round; wing narrow
Ecology: Rocky slopes, valleys
Elevation: < 2800 m.
Bioregional distribution: Cascade Range, Sierra Nevada Foothills, Southwestern California, Great Basin Floristic Province, n Desert Mountains
Distribution outside California: to British Columbia, Montana, Wyoming, Utah
| Native |
var. sparsiflora
Stem generally branched above; hairs spreading, simple below, ± 0 to very sparse above
Leaves: basal linear-oblanceolate, entire
Fruit: pedicel ascending; hairs ± 0 (to sparse, spreading)
Ecology: Steep, gravelly slopes, grassy sagebrush, basaltic talus
Elevation: 1300–2800 m.
Bioregional distribution: Great Basin Floristic Province, n Desert Mountains
Distribution outside California: to Idaho, Utah
Flowering time: May–Jul
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