Lepidium perfoliatum L.
Family: Brassicaceae
clasping pepperweed,  more...
Lepidium perfoliatum image
Patrick Alexander  
Annuals or biennials; (glaucous), glabrous or sparsely pubescent proximally. Stems simple from base, erect, branched distally, (0.7-)1.5-4.3(-5.6) dm. Basal leaves rosulate; petiole (0.5-) 1-2(-4) cm; blade 2- or 3-pinnatifid or pinnatisect (lobes linear to oblong), (1-)3-8(-15) cm, margins entire. Cauline leaves sessile; blade ovate to cordate or suborbicular, (0.5-)1-3 (-4) cm × (5-)10-25(-35) mm, base deeply cordate-amplexicaul, not auriculate, margins entire. Racemes considerably elongated in fruit; rachis glabrous. Fruiting pedicels divaricate-ascending to horizontal, straight, (terete), 3-6(-7) × 0.2-0.3 mm, glabrous. Flowers: sepals oblong, 0.8-1(-1.3) × 0.5-0.8 mm; petals pale yellow, narrowly spatulate, 1-1.5(-1.9) × 0.2-0.5 mm, claw 0.5-1 mm; stamens 6; filaments 0.6-0.9 mm, (glabrous); anthers 0.1-0.2 mm. Fruits orbicular to rhombic or broadly obovate, 3-4.5 (-5) × 3-4.1 mm, apically winged, apical notch 0.1-0.3 mm deep; valves thin, smooth, not or obscurely veined, glabrous; style 0.1-0.4 mm, subequaling or slightly exserted beyond apical notch. Seeds (dark brown), ovate, 1.6-2(-2.3) × 1.2-1.4 mm. 2n = 16. Flowering Mar-Jun. Waste places, dry sandy slopes, pinyon-juniper woodlands, sagebrush flats, open deserts, roadsides, pastures, meadows, open grasslands, alkaline flats and sinks, fields, disturbed sites; 0-2500 m; introduced; Alta., B.C., Man., Ont., Sask.; Ariz., Ark., Calif., Colo., Conn., Ga., Idaho, Ind., Iowa, Kans., Maine, Mass., Mich., Miss., Mo., Mont., Nebr., Nev., N.Mex., N.Y., N.C., Ohio, Okla., Oreg., Pa., S.Dak., Tenn., Utah, Wash., Wis., Wyo.; Europe; Asia; n Africa; introduced also in Mexico (Baja California), South America (Argentina), Australia.
Annual herb 20 cm - 0.5 m tall Stem: upright, branched near the apex, sparsely hairy. Flowers: in branched clusters (raceme). Sepals four, 1 - 1.3 mm long, broadly oval, and firm. Petals four, yellow, 1 - 1.5 mm long, narrowly spatula-shaped. Stamens six. Fruit: a small pod, 4 mm long, 3 mm wide, diamond-shaped to elliptic, flattened, obscurely notched. Lower leaves: pinnately divided into linear segments, sparsely hairy. Upper leaves: alternate, clasping, stalkless, much shorter than lower leaves, heart-shaped, bases lobed, tips pointed, lobes long and usually overlapping, sparsely hairy.

Similar species: Lepidium perfoliatum and Lepidium campestre are the only Lepidium species with lobed, clasping leaves. Lepidium campestre differs by being densely hairy all over.

Flowering: late May to early June

Habitat and ecology: Introduced from Europe. A weed found in disturbed areas, especially along roads and railroads.

Occurence in the Chicago region: non-native

Etymology: Lepidium comes from the Greek word lepis, meaning scale, which refers to the shape of the fruit. Perfoliatum means "with the leaf surrounding the stem."

Author: The Morton Arboretum

Erect, sparsely hairy annual 2-5 dm, branched above; basal and lower cauline lvs pinnately dissected into linear segments; upper cauline lvs broadly ovate to subrotund, entire, deeply cordate, the rounded auricles about as long as the rest of the blade and usually overlapping; sep firm, broadly oval, 1-1.3 mm; pet narrowly spatulate, yellow, 1-1.5 mm; stamens 6; fr rhombic-elliptic, 4 נ3 mm, obscurely retuse; style about as long as the notch; 2n=16. Native of Europe, well established as a weed in w. U.S., e. to Mich. and O. and occasionally elsewhere in our range. May, June.Erect, sparsely hairy annual 2-5 dm, branched above; basal and lower cauline lvs pinnately dissected into linear segments; upper cauline lvs broadly ovate to subrotund, entire, deeply cordate, the rounded auricles about as long as the rest of the blade and usually overlapping; sep firm, broadly oval, 1-1.3 mm; pet narrowly spatulate, yellow, 1-1.5 mm; stamens 6; fr rhombic-elliptic, 4 נ3 mm, obscurely retuse; style about as long as the notch; 2n=16. Native of Europe, well established as a weed in w. U.S., e. to Mich. and O. and occasionally elsewhere in our range. May, June.

Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.

©The New York Botanical Garden. All rights reserved. Used by permission.
General: Introduced annual (sometimes biennial), 10-60 cm tall; stems single from base, erect, branched above; taprooted. Leaves: Strongly dimorphic, glaucous, basal leaves bi- or tripinnatifid with linear segments, 3.5-14 cm long, the segments entire; lower cauline leaves as described above, gradually reduced and modified upwards, the upper cauline leaves appearing perfoliate, ovate to orbicular, 1.4-3 cm long, margins entire, the base cordate, deeply clasping. Flowers: Inflorescence of numerous racemes, many-flowered, congested in flower and elongating somewhat in fruit; fruiting pedicels nearly round in cross-section, 3.5-8.5 mm long; sepals 1.1-2 mm long; petals oblanceolate to orbicular from a narrow claw, 2-3.5 (4.5) mm long, greatly surpassing the sepals, white to cream; stamens 6; flowers April-September. Fruits: Silicle, broadly obovate or rhombic-ovate to sub- orbicular, flattened, 3.7-4.5 (5) mm long, 3-4.2 mm wide, the apex scarcely notched (about 0.2 mm deep); mature style small, 0.2-0.4 mm long, equaling or exserted slightly beyond the notch; seeds brownish Ecology: Disturbed habitats, roadsides, agricultural lands; 1100- 2100 m (3500-7000 ft); Apache, Coconino, Navajo, and Pima counties; widespread throughout the U.S. Notes: This species, though not typically of forest habitat, is well documented in the vicinity of the San Francisco Peaks, specifically around Flagstaff. Editor: Springer et al. 2008
Lepidium perfoliatum image
Patrick Alexander  
Lepidium perfoliatum image
Patrick Alexander  
Lepidium perfoliatum image
Patrick Alexander  
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Stephen Stern  
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Stephen Stern  
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
Lepidium perfoliatum image
The National Science Foundation
This project made possible by National Science Foundation Award 1410069