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.
RORIPPA
YELLOW or WATER CRESS
Annual, biennial, perennial herb; hairs simple, rarely sac-like
Stems 1–many, prostrate to erect, branched or not, often from center of basal rosette, rooting at nodes or not
Leaves: basal, lower cauline sessile or short-petioled, entire to pinnately compound; cauline reduced upward
Inflorescence terminal and lateral
Flower generally small; petals 0 or obovate to narrowly spoon-shaped, pale to bright yellow or white
Fruit linear to round, plump; valves 2 or 4(6); pedicel ascending to recurved, slender, generally with 2 minute glands at base; style 0 or prominent, persistent
Seeds 10–200, (1)2 rows per chamber, dense, generally plump; wing 0; embryonic root at edges of both cotyledons
Species in genus: ± 75 species: worldwide
Etymology: (Old Saxon: for these, perhaps other crucifers)
Reference: [Stuckey 1972 Sida 4:277–340]
| Native |
R. subumbellata Rollins
TAHOE WATER CRESS
Perennial
Stems several, decumbent, 5–15(20) cm, branched; hairs generally crinkled
Leaf sessile to short-petioled, clasping stem or not, 1–3 cm, oblong to widely oblanceolate, wavy-margined to deeply pinnately lobed; hairs 0 or sparse
Inflorescence ± umbel-like to ± elongate
Flower: sepals 2–3 mm, yellowish, glabrous, persistent in fruit; petals 2.5–3.5 mm, oblong-oblanceolate to spoon-shaped, yellow
Fruit 3–5 mm, widely oblong to ± round, ± glabrous; pedicel erect to ascending, 3–6 mm, straight; style 1–1.5 mm, glabrous, stigma ± unexpanded
Seed ± 1 mm, plump, ± angled
Ecology: Sandy lake margins
Elevation: 1800–2500 m.
Bioregional distribution: n High Sierra Nevada (Lake Tahoe Basin)
Distribution outside California: w Nevada
previous taxon | next taxon
Retrieve Jepson Interchange Index to Plant Names entry for Rorippa subumbellata
Retrieve dichotomous key for Rorippa
Return to treatment index page
Glossary