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. palustris (L.) Besser
Annual, biennial, short-lived perennial herb, ± erect, with 1 dominant stem from base
Stem > 3 mm diam; branches 0 or ± from base
Leaves: basal and lower cauline short-petioled to sessile, ± clasping stem or not, 5–20(30) cm, oblong to oblanceolate, irregularly dentate to deeply pinnately lobed
Flower: petals 1–2.5(3.5) mm, widely spoon-shaped, yellow
Fruit generally > 2 mm wide, straight to ± upcurved; pedicel spreading to ascending, 2–14 mm; style 0.2–1 mm, abruptly attached to fruit tip
Seed 0.5–1 mm, widely reniform
Ecology: Generally wet areas
Elevation: < 2000 m.
Bioregional distribution: California
Distribution outside California: temperate N.America, Eurasia
10 vars. total.
| Native |
var. hispida (Desv.) Rydb.
Stem 4–10 dm; hairs ± dense
Leaf hairy on both surfaces
Fruit 2–6 mm, widely ovate to round
Chromosomes: 2n=32
Ecology: Wet woods, ditches, moist depressions
Elevation: 1200–1500 m.
Bioregional distribution: Modoc Plateau
Distribution outside California: to Alaska, New Mexico
Synonyms: R. islandica (Oeder) Borbás var. h. (Desv.) Butters & Abbe
previous taxon | next taxon
Retrieve Jepson Interchange Index to Plant Names entry for Rorippa palustris var. hispida
Retrieve dichotomous key for Rorippa
Return to treatment index page
Glossary