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lesser pepper-grass, lesser swine-cress, lesser wart-cress

narrow-leaf pepper-grass, roadside pepper-grass, roadside pepperweed, stinking pepper-weed

Habit Annuals; (fetid); glabrous or pilose. Annuals or biennials; (fetid); puberulent (trichomes cylindrical).
Stems

few to several from base, erect to ascending or decumbent, branched distally, 1–4.5(–7) dm.

simple from base, erect ascending, branched (several) distally, (0.5–)1–3.5(–5.5) dm.

Basal leaves

(soon withered);

not rosulate;

petiole 0.5–4(–6) cm;

blade 1- or 2-pinnatisect, 1–6(–8) cm, margins (of lobes) entire or dentate (sometimes deeply lobed).

rosulate;

petiole 1–3.2(–5.3) cm;

blade (1- or) 2- or 3-pinnatisect (lobes oblong), (1.5–)3–5(–7.2) cm, margins (of lobes) usually entire, rarely dentate.

Cauline leaves

shortly petiolate to subsessile;

blade similar to basal, smaller and less divided distally, lobes lanceolate to oblong or elliptic, 1.5–3.5(–4.5) cm ×5–12 mm, base not auriculate, margins (of lobes) entire, serrate, or incised.

sessile;

blade linear, (0.4–)1–2(–3) cm × 0.5–2.5(–3.5) mm, base cuneate, not auriculate, margins entire.

Racemes

elongated in fruit;

rachis glabrous or pubescent, trichomes straight, cylindrical.

considerably elongated in fruit;

rachis puberulent, trichomes straight, cylindrical.

Flowers

sepals (tardily deciduous), ovate, 0.5–0.7(–0.9) mm;

petals white, elliptic to linear, 0.4–0.5 × ca. 0.1 mm, claw absent;

stamens 2, median;

filaments 0.3–0.6 mm;

anthers 0.1–0.2 mm.

sepals oblong, 0.5–0.9(–1) × 0.2–0.4 mm;

petals (absent or rudimentary), white, linear, 0.2–0.5 × 0.1 mm, claw absent;

stamens 2, median;

filaments 0.7–0.8 mm;

anthers 0.1–0.2 mm.

Fruiting pedicels

divaricate to horizontal, straight slightly recurved, (terete), 1.4–2.5(–4) × 0.15–2 mm, glabrous or sparsely pubescent adaxially.

divaricate to horizontal, straight, (terete), (1.5–)2–4(–5) × 0.1–0.15 mm, puberulent.

Fruits

schizocarpic, didymous, 1.3–1.7 × 2–2.5 mm, apically not winged, apical notch 0.2–0.4 mm deep;

valves thick, rugose, strongly veined, glabrous;

style absent or obsolete, included in apical notch.

elliptic, (1.5–)1.8–2.5(–3) × 1.5–2(–2.3) mm, apically winged, apical notch 0.1–0.2 mm deep;

valves thin, smooth, not veined, glabrous;

style obsolete or to 0.1 mm, included in apical notch.

Seeds

ovate, 1–1.2 × 0.7–0.8 mm.

oblong to ovate-oblong, 1–1.5 × 0.6–0.8 mm.

2n

= 32.

= 16, 32.

Lepidium didymum

Lepidium ruderale

Phenology Flowering Mar–Jul. Flowering Apr–Jul.
Habitat Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas Fields, pastures, waste places, roadsides, gardens
Elevation 0-1000 m (0-3300 ft) 0-300 m (0-1000 ft)
Distribution
from FNA
AL; AR; AZ; CA; CT; FL; GA; LA; MA; MD; ME; MO; MS; NC; NJ; NY; OH; OR; PA; SC; TN; TX; VA; WI; WV; BC; NB; NF; NS; QC; South America [Introduced in North America; introduced also in Mexico (Sinaloa), Central America (Honduras), Europe, Asia, s Africa, Australia]
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; CA; DE; FL; IN; LA; MA; MD; ME; MI; NC; NH; NJ; NM; NY; OH; OR; PA; RI; TN; TX; AB; BC; MB; NB; NF; NS; ON; PE; QC; SK; Eurasia [Introduced in North America; introduced also in South America, Australia]
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 7, p. 580. FNA vol. 7, p. 592.
Parent taxa Brassicaceae > tribe Lepidieae > Lepidium Brassicaceae > tribe Lepidieae > Lepidium
Sibling taxa
L. acutidens, L. alyssoides, L. appelianum, L. austrinum, L. barnebyanum, L. campestre, L. chalepense, L. coronopus, L. crenatum, L. davisii, L. densiflorum, L. dictyotum, L. draba, L. eastwoodiae, L. flavum, L. fremontii, L. heterophyllum, L. huberi, L. integrifolium, L. jaredii, L. lasiocarpum, L. latifolium, L. latipes, L. montanum, L. nanum, L. nitidum, L. oblongum, L. ostleri, L. oxycarpum, L. papilliferum, L. paysonii, L. perfoliatum, L. pinnatifidum, L. ramosissimum, L. ruderale, L. sativum, L. sordidum, L. strictum, L. thurberi, L. tiehmii, L. virginicum
L. acutidens, L. alyssoides, L. appelianum, L. austrinum, L. barnebyanum, L. campestre, L. chalepense, L. coronopus, L. crenatum, L. davisii, L. densiflorum, L. dictyotum, L. didymum, L. draba, L. eastwoodiae, L. flavum, L. fremontii, L. heterophyllum, L. huberi, L. integrifolium, L. jaredii, L. lasiocarpum, L. latifolium, L. latipes, L. montanum, L. nanum, L. nitidum, L. oblongum, L. ostleri, L. oxycarpum, L. papilliferum, L. paysonii, L. perfoliatum, L. pinnatifidum, L. ramosissimum, L. sativum, L. sordidum, L. strictum, L. thurberi, L. tiehmii, L. virginicum
Synonyms Carara didyma, Coronopus didymus, Senebiera didyma, Senebiera incisa, Senebiera pinnatifida L. texanum, L. virginicum subsp. texanum
Name authority Linnaeus: Syst. Nat. ed. 12, 2: 433. (1767): Mant Pl. 1: 92. (1767) Linnaeus: Sp. Pl. 2: 645. (1753)
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