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

Idaho pepperweed

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

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

several from base, ascending, branched (several) distally, (0.3–)0.5–2.3(–4) 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).

(soon deciduous), not rosulate;

blade often bipinnately divided.

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.

attenuate to petiolelike base, to 1 cm;

blade pinnatifid to pinnatisect, obovate to oblanceolate in outline (lobes oblong to linear), 0.5–4 cm × 3–15 mm (smaller distally), base not auriculate, margins (of lobes) entire or dentate.

Racemes

elongated in fruit;

rachis glabrous or pubescent, trichomes straight, cylindrical.

slightly elongated, (dense) in fruit;

rachis puberulent, trichomes straight or curved, clavate.

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 ovate to broadly oblong, 1.5–2.2 × 0.8–1.1 mm;

petals white, orbicular to spatulate, 2.5–3.7(–4) × 1.5–2.5 mm, claw 0.8–1.5 mm;

stamens 6;

filaments 1.5–2 mm, (trichomes clavate);

anthers 0.4–0.6 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 or recurved, (not winged), (2.5–)3–6(–7.5) × 0.2–0.3 mm, puberulent adaxially or throughout.

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.

orbicular to broadly ovate, 2.2–3.6 × 2–3.4 mm, apically winged, apical notch 0.1–0.3 mm deep;

valves thin, smooth, often not veined, glabrous;

style 0.2–0.8 mm, exserted beyond apical notch.

Seeds

ovate, 1–1.2 × 0.7–0.8 mm.

ovate, 1.2–1.8 × 0.9–1.1 mm.

2n

= 32.

Lepidium didymum

Lepidium papilliferum

Phenology Flowering Mar–Jul. Flowering May–Jun.
Habitat Roadsides, waste areas, lawns, pastures, fields, gardens, disturbed areas Sagebrush plains, desert flats, edge of playa
Elevation 0-1000 m (0-3300 ft) 600-1700 m (2000-5600 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
ID
[BONAP county map]
Discussion

Of conservation concern.

Lepidium papilliferum is distributed in Ada, Canyon, Elmore, Gem, Owyhee, and Payette counties.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 7, p. 580. FNA vol. 7, p. 590.
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. paysonii, L. perfoliatum, L. pinnatifidum, L. ramosissimum, L. ruderale, L. sativum, L. sordidum, L. strictum, L. thurberi, L. tiehmii, L. virginicum
Synonyms Carara didyma, Coronopus didymus, Senebiera didyma, Senebiera incisa, Senebiera pinnatifida L. montanum var. papilliferum, L. montanum subsp. papilliferum
Name authority Linnaeus: Syst. Nat. ed. 12, 2: 433. (1767): Mant Pl. 1: 92. (1767) (L. F. Henderson) A. Nelson & J. F. Macbride: Bot. Gaz. 56: 474. (1913)
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