A N F Keys
1 Siliqua length > 2.5× width; petals of various colors or white
2 Stamens > petals, filaments 19−28 mm long and subequal, long-pubescent to short-pilose at base; pistil stalked, the stalk (gynophore) at anthesis ± 10 mm long increasing to 15−19 mm long in fruit; flowers bright yellow .. Stanleya pinnata var. pinnata [pics]
2' Stamens < petals, filaments to 13.5 mm long, mostly dimorphic with outer pair shorter than inner whorl, glabrous; pistil not stalked or scarcely so in fruit
3 Shoots with branched hairs
4 Leaves 2−3-pinnately compound and dissected, sometimes also densely glandular-pubescent (Descurainia pinnata); petals 1−2.5 mm long, limbs bright yellow or light yellow .. Descurainia
4' Leaves either all unlobed or at most pinnately lobed, never glandular-pubescent
5 Diminutive and acaulous annuals, having a narrow basal rosette and lacking cauline leaves; flowers ca. 1 mm across, with minute, white petals (to 0.6 mm long) rounded or notched at tip; siliquas ± elliptic in outline and slightly inflated, ± 8 × 2−2.5 mm long, densely pubescent with branched hairs .. Draba cuneifolia [pics]
5' Plants with cauline leaves
6 Blades of basal and cauline leaves pinnately dissected; flowers often appearing axillary or in several-flowered racemes; petals vivid yellow; siliquas (siliques) linear, 40−50 × 1.5−2 mm, sometimes twisted 90° at base, flattened ⊥ septum .. Tropidocarpum gracile [pics]
6' Cauline leaves always unlobed; flowers always in many-flowered racemes; siliquas never twisted at base
7 Petals pale yellow; plants 80−180 cm tall, having overlapping and clasping cauline leaves and a long raceme with straight, overlapping erect siliques, 65−85 × 1−1.3 mm .. Turritis glabra [pics]
7' Petals pigmented and colorful
8 Cauline leaves clasping; sepals and petals dark violet to dark purple; siliques lacking beak .. Boechera sparsiflora [pics]
8' Cauline leaves not clasping; petals light yellow, golden yellow, or light orange; siliques with beak .. Erysimum
3' Shoots glabrous or having only unbranched hairs
9 Fruits indehiscent, halves not separating lengthwise along septum, some breaking transversely into 1-seeded segments
10 Leaves with large, coarse lobes and thick petioles and principal veins conspicuously raised on lower surface of blades; flowers with petals varied within population from light purple and lavender and other shades, sometimes white or pale yellow, often with prominent venation on limbs; fruits drying as a hard, lanceoloid unit bulging at seeds with thick fruit wall and a long-tapered beak, in certain species breaking into 1-seeded segments; weeds of disturbed habitats .. Raphanus
10' Leaves with linear lobes or only low-toothed, somewhat fleshy; flowers light purple, lavender, purplish, to white; fruits breaking into a larger upper segment and a persistent lower segment; plants restricted to sand dunes .. Cakile
9' Fruits dehiscent, halves separating lengthwise along septum
11 Flowers yellow or yellowish
12 Stigma obviously 2-lobed
13 Leaves ill-smelling, lower surface of blade with many raised glands visible (7×); petals 5−7 mm long, clawed with a lemon yellow limb; silique stalked to 1 mm, (12−)20−45 mm long including beak 1−2 mm long, with midvein on each valve, glabrous .. Diplotaxis tenuifolia
13' Leaves not ill-smelling, lower surface of blade lacking raised glands; petals various shades of white (white); silique lacking stalk, with or without beak, midvein on each valve not conspicuous, glabrous or long-hairy .. Sisymbrium
12' Stigma capitate or inconspicuously 2-lobed
14 Flowers tiny with sepals 1.8−2.3 mm long and petals 1.3−1.9 mm long; siliques short, sausage-shaped, 5.5−10 × 1.8−2 mm (including stout beak) .. Rorippa curvisiliqua [pics]
14' Flowers larger with longer sepals and petals; siliques 10+ mm long
15 Siliques erect and appressed to inflorescence axis, < 18 mm long (including beak)
16 Foliage scabrous, hirsute to short-strigose; anthers in bud with deep purple spot at tip; beak ridged, with seed .. Hirschfeldia incana [pics]
16' Foliage hispid on lower leaves but ± glabrous above midplant; anthers in bud only yellow; beak 1.3−3 mm long, but neither ridged nor containing a seed .. Brassica nigra [pics]
15' Siliques not appressed to inflorescence axis, 25+ mm long (including beak)
17 Foliage glossy green; flowers 5−6 mm across; petals not clawed, 3.5−5 mm long; silique beak absent .. Barbarea orthoceras [pics]
17' Foliage of rosette leaves ± hispid; flowers 6−11 mm across; petals clawed, 5.3−10 mm long; siliques with beak .. Brassica (part)
11' Flowers not yellow
18 Siliques strongly reflexed or not; petals not clawed, white to cream-colored or with greenish yellow veins, sometimes reddish purple .. Caulanthus
18' Siliques spreading, ascending, or erect; petals clawed
19 Aquatic herbs with pinnately compound leaves, forming roots at nodes; flowers white; siliques ± cylindric, 10−17 × 2.2−3 mm .. Nasturtium officinale [pics]
19' Herbs, not aquatic, with 3-foliolate to pinnately compound leaves, never forming roots at nodes; flowers pale lavender to pinkish or white; siliques opening elastically by valves coiling upward from base .. Cardamine
1' Siliqua length < 2.5× width and strongly compressed to flat (silicles); petals white (absent), sometimes pale yellow
20 Silicles abscising into 2 distinct halves ⊥ flat surface
21 Hairs mostly branched; silicle triangular with pointed base and broad top, many-seeded .. Capsella bursa-pastoris [pics]
21' Hairs unbranched; silicle roundish with notch at top or at top and bottom, 2-seeded .. Lepidium
20' Silicles not abscising ⊥ flat or compressed surface
22 Perennial herbs; shoots with only cauline leaves, hairs T-shaped with 2 arms appressed to surfaces; flowers strongly honey-scented; silicles several-seeded and dehiscent, compressed-ovoid to ellipsoid, 3.3−4 × 1.7−2 mm .. Lobularia maritima [pics]
22' Annuals; hairs not T-shaped with appressed arms
23 Silicle several−many-seeded and dehiscing; hairs on shoot mostly unbranched but with scattered branched hairs
24 Plants 13−70 cm tall; petals pale yellow; silicle compressed-obovoid, 3.5−5(−7) × 2−4(−5) mm .. Camelina microcarpa
24' Plants < 18 cm tall; petals white; silicle cylindric, (8−)10−15 × 5−8 mm .. Arabidopsis thaliana
23' Silicle 1-seeded and indehiscent
25 Shoots glabrous or with scattered, unbranched hairs; silicles 2.5+ mm long, with a circular wing sometime perforated .. Thysanocarpus
25' Shoots with mostly branched; silicles 1−2.5 mm long, lacking an encircular wing and bearing hooked hairs .. Athysanus pusillus [pics]
1 Plants with well-developed basal rosette when in flower; petals typically 5.3−6.5 mm long, pale light yellow; siliquas mostly spreading .. Brassica tournefortii [pics]
1' Plants appearing to have only cauline leaves when in flower; petals 9−13 mm long, bright yellow; siliquas ascending to erect
2 At least upper cauline leaves conspicuously clasping and glaucous; pedicels at maturity > 12 mm long; claw of petal winged base to top, stigma often visible or slightly exserted prior to anthesis; siliquas 32−53 mm long (incl. beak 11−15 mm long) .. Brassica rapa [pics]
2' Cauline leaves neither clasping nor noticeably glaucous; pedicels at maturity 5−6 mm long and appressed to rachis; claw of petal winged only at base, stigma not visible prior to anthesis; siliquas < 20 mm long (incl. short beak) .. Brassica nigra [pics]
1 Lower leaves deeply pinnately lobed; petals clawed, 8−14 mm long, light purple to lavender (deep purple, white); upper segment of siliqua inversely urn-shaped to spheroid, 8−16 mm long, with conic to cylindric beak, lower segment with a pair of lateral lobes .. Cakile maritima [pics]
1' Lower leaves toothed to shallowly lobed, never deeply pinnately lobed; petals present or absent, not clawed, (4.5−)6−8 mm long, purplish to white; upper segment of siliqua inversely top-shaped and 4-angled, 12−24 × 5−9 mm, with very short, blunt beak, lower segment 4-angled and lacking lateral lobes .. Cakile edentula var. edentula
1 Perennial herb, with 1 separate, basal leaf arising from a thickened rhizome, blades of leaflets 20−80 mm long; flowers showy, petals 11−13 mm long; siliquas 40−45 mm long .. Cardamine californica [pics]
1' Annual, with basal rosette and taproot, blades of leaflets 3−20 mm long; flowers not conspicuous, petals 2−4 mm long; siliquas 10−25 mm long .. Cardamine oligosperma [pics]
Caulanthus S.
Watson
JEWELFLOWER, WILD-CABBAGE
1 Cauline leaves petiolate, petioles to 10 mm long and channeled; flowers 3−4 mm across; sepals 2.7−3.2 × 0.8−1 mm; petals 3−4.5 mm long, white to cream-colored, faintly veined; beak on siliquas short or absent .. Caulanthus lasiophyllus [pics]
1' Cauline leaves sessile and with clasping blade bases (auricles) 4 mm long; flowers 8−9 mm across; sepals 6.5−8.5 × 2 mm; petals 11−13.5 mm long, yellowish, conspicuously pinnately veined, the veins purple and green; beak on siliquas ca. 2.5 mm long .. Caulanthus heterophyllus [pics]
Descurainia Webb & Berthel.
TANSY MUSTARD
1 Shoots with stalked glandular hairs among branched nonglandular hairs, foliage grayish green and densely hairy; pedicels at anthesis 3−5 mm long; petals 1.5−2 mm long; filaments 1.3−1.6 mm long; siliquas fusiform-elliptic, 5−12 × 1.5−2 mm .. Descurainia pinnata subsp. brachycarpa [pics]
1' Shoots lacking glandular hairs among branched nonglandular hairs, foliage green and sparsely hairy; pedicels at anthesis 7−8 mm long; petals 2.4−2.5 mm long; filaments 2.6−3.3 mm long; siliquas linear, 15−31 × 0.9 mm .. Descurainia sophia [pics]
1 Subshrub with many branches at base, to 35 cm tall; principal blades < 80 × 1.3−3.5 mm; flowers ± 15 across, bright yellow; siliqua 30−85 mm long including beak ca. 1 mm .. Erysimum suffrutescens [pics]
1' Herb (biennial) with 1 dominant shoot, 30−115 cm tall; principal blades > 80 × 5.5−16 mm; flowers 20−25 mm across, golden yellow to light orange; siliqua typically 80−145 mm long including beak 1.5−3 mm long .. Erysimum capitatum var. capitatum [pics]
Lepidium L.
PEPPERGRASS,
PEPPERWEED
1 Perennial herbs
2 Plants 20−55 cm tall; shoots uniformly puberulent with arching hairs; leaves clasping with basal lobes; petals 1.3−2(−2.3) mm long; siliquas (silicles) heart-shaped with glabrate valves .. Lepidium draba [pics]
2' Plants 60−120(−200) cm tall; shoots villous to ± glabrous; leaves not clasping; petals ± 3 mm long; siliquas (silicles) round with sparsely villous valves .. Lepidium latifolium [pics]
1' Annuals
3 Pedicels noticeably flattened in fruit
4 Siliquas 5−5.5 mm long with two acute wings at top; notch between wings narrow and ca. 2 mm deep .. Lepidium latipes [pics]
4' Siliquas roundish in outline; notch short
5 Siliquas glabrous, 3.5−5.4 × 3.3−4.5 mm; stamens 2−4 .. Lepidium nitidum [pics]
5' Siliquas pubescent, 3−3.5(−4) × 2.8−3 mm; stamens 2 .. Lepidium lasiocarpum subsp. lasiocarpum [pics]
3' Pedicels ± cylindric to slightly flattened in fruit
6 Siliquas lobed top and bottom, 1.7−2 × 3 mm, initially valves beadlike becoming netlike .. Lepidium didymum [pics]
6' Siliquas lobed only at top; valves ± smooth or drying slightly veined
7 Siliquas 3.5−4 mm long .. Lepidium pinnatifidum
7' Siliquas 2−3 mm long
8 Cauline leaves pinnately divided to cut-lobed; sepals persistent until fruit almost mature .. Lepidium strictum [pics]
8' Cauline leaves entire to somewhat jagged-toothed .. Lepidium virginicum subsp. menziesii [pics]
NB. Lepidium appelianum Al-Shehbaz, formerly Cardaria pubescens (C. A. Meyers) Rollins, was reported in range but was not encountered during the study and living material was unavailable to produce a description. This species differs in small ways from L. draba, formerly also treated as a species of Cardaria.
We have no confidence that all species of Lepidium occurring in range have been found. Because lepidiums are small and weedy, they are unlikely to draw much attention. Moreover, distinguishing the species can also be challenging because parts are small and features often used for separating species have qualitative and phenologic components that raise issues in final decisions.
1 Basal leaves 7−16-lobed, petioles of large leaves 50−120 mm long; petals light yellow to white (occasionally reddish purple), anthers 2.8−3.5 mm long; siliquas 3.5−5 mm wide, conspicuously constricted between seeds (torulose), with slender beak to 17 mm long, horizontally breaking into 1-seeded segments; seeds tannish .. Raphanus raphanistrum [pics]
1' Basal leaves 4−8-lobed, petioles of the largest leaves < 50 mm long; petals reddish purple (occasionally white, never yellow), anthers 2.3−3 mm long; siliquas 6−8 mm wide, not constricted between seeds, with conic beak, not breaking into 1-seeded segments; seeds cinnamon brown to golden buff .. Raphanus sativus [pics]
1 Siliquas erect and appressed to inflorescence axis, 9−17 mm long, beak 1.3−3 mm long .. Sisymbrium officinale [pics]
1' Siliquas ascending to widely spreading from inflorescence axis, > 35 mm long
2 Leaves ± glabrous; flowers 3−4 mm across, stamens ± equal; siliquas 35−50 × 1 mm, beak 0−0.4 mm long .. Sisymbrium irio [pics]
2' Leaves pilose-hirsute to villous; flowers 7−10 mm across; stamens dimorphic; siliqua > 55 mm long
3 Uppermost cauline leaves conspicuously pinnately lobed; siliquas lacking beak .. Sisymbrium altissimum [pics]
3' Uppermost cauline leaves unlobed; siliqua beak club-shaped to bulbous, 1−1.5 mm long .. Sisymbrium orientale [pics]
Thysanocarpus Hooker
LACEPOD, FRINGEPOD
1 Plants 2.5−12 cm tall, often senescing light purple; flowers 4.5−6 mm across, petals 2.4−2.9 mm long; siliquas 2.5−3.4 mm across, wing conspicuously lobed with deep sinuses and lobes brilliantly deep purplish red (brown when dry) .. Thysanocarpus conchuliferus [pics]
1' Plants 10−60 cm tall, green or purplish red; flowers 1−1.5 mm across, petals ca. 1 mm long; siliquas typical 4−8 mm across, wing shallowly lobed, sometimes with perforations, but never deep purplish red on wings (scarious when dry)
2 Basal leaves pinnately dissected with several slender lobes, leaves typically not clasping stem; siliquas mostly glabrous, with beak 0.4−0.6 mm long .. Thysanocarpus laciniatus var. laciniatus [pics]
2' Basal leaves several-toothed, leaves clasping stem; siliquas mostly densely short-hairy on faces, with beak 0.4−2 mm long .. Thysanocarpus curvipes [pics]
The text of the above keys used with permission from
A Naturalist's Flora of the Santa Monica Mountains and Simi Hills, California
© Copyright
Barry A. Prigge and Arthur C. Gibson
2013