Clasping Pepperweed

Easily distinguished by its dimorphic leaves and yellow flowers.

Sometimes eaten as a vegetable or used medicinally as an antiscorbutic.

Annual or biennial, 15-30 cm tall, erect, branched mostly above, subhairy below with simple hairs, glabrous or subglabrous above. Leaves dimorphic; lower leaves bipinnatisect, 5-10 cm long, 1.5-2.5 cm broad, short stalked; lobes narrowly linear, short, acute; middle and upper leaves ovate-cordate, sessile, amplexicaul, 1-1.5 cm long, 1-2 cm broad, entire, acute; all leaves somewhat fleshy, ± glabrous. Racemes 30-70-flowered, ebracteate, up to 8 cm long in fruit. Flowers small, c. 2 mm across, pale yellow; pedicel up to 7 mm long in fruit, filiform, spreading or ascending. Sepals c. 1 mm long, 0.6 mm broad, oblong, obtuse. Petals c. 1.7 mm long, 0.5 mm broad, oblong-spathulate, clawed, apex rounded. Stamens 6, c. 1: 1.4 mm long with minute anthers. Siliculae 3-4 mm in diam., suborbicular or broadly elliptic, slightly winged and notched at the apex; style short with capitate stigma slightly protuding out of the notch; valves thin, obscurely winged; septum c. 1 mm broad; seed c. 2 mm long, ovate-oblong, reddish brown.

Herbs annual or biennial, (7-)15-40(-65) cm tall, glabrous throughout or sparsely pubescent below, often slightly glaucous. Stems erect, simple at base, branched above. Leaves strongly dimorphic. Basal and lowermost cauline leaves with petioles (0.5-)1-2(-4) cm; leaf blade 2- or 3-pinnatifid or -pinnatisect, (1-)3-8(-15) cm; ultimate lobes linear or narrowly oblong. Upper cauline leaves sessile; leaf blade broadly ovate, cordate, or suborbicular, (0.5-)1-3(-4) × (0.5-)1-2.5(-3.5) cm, base deeply cordate-amplexicaul, margin entire, apex acute. Fruiting pedicels divaricate, 3-5(-7) mm, slender, straight, glabrous, terete. Sepals yellowish green, oblong, 0.8-1(-1.3) × 0.5-0.8 mm. Petals yellow, narrowly spatulate, 1-1.5(-1.9) × 0.2-0.5 mm, base attenuate to a claw ca. 0.5 mm. Stamens 6; filaments 0.6-0.9 mm; anthers 0.1-0.2 mm. Fruit rhombic or orbicular, 3-4.5(-4.8) × 3-4 mm narrowly winged distally; wings apical, 0.2-0.4 mm; apical notch to ca. 0.3 mm; style 0.1-0.3 mm, as long as or shorter than apical notch. Seeds dark brown, ovate, 1.6-2(-2.3) × 1.2-1.4 mm, narrowly winged all around; cotyledons incumbent. Fl. Mar-Jun, fr. May-Jul. 2n = 16.

Distribution: C. and S. Europe, eastward to Pakistan.

Gansu, Jiangsu, Liaoning, Shanxi, Xinjiang [Afghanistan, India, Japan, Kazakhstan, Kyrgyzstan, Pakistan, Russia, Tajikistan, Turkmenistan, Uzbekistan; N Africa, SW Asia, Europe; introduced elsewhere].

Fl. Per.: March-July.

Waste places, dry sandy slopes; near sea level to 1000 m.

Lepidium perfoliatum is a species of flowering plant in the mustard family known by the common names clasping pepperweed and perfoliate pepperwort. It is native to Europe and Asia and it can be found in other parts of the world as an introduced species.

This is an annual or biennial herb producing an erect stem to a maximum height near 60 centimeters. Leaves at the base of the plant are divided into linear lobes, while the leaves higher up on the stem are rounded to oval in shape and surround the stem. The tip of the stem is occupied by an inflorescence of very small flowers, each with yellow petals only 1 or 2 millimeters (0.039 or 0.079 in) long. The fruit is a flattened oval or diamond-shaped capsule about 4 millimeters (0.16 in) long.