Shepherd's Purse

‘Shepherds purse’ is a very variable species, especially in size and shape of leaves, siliculae and hairiness. It has strong tendency for developing distinctive populations because of self pollination. Some of its forms superficially resemble C. rubella Reuter, from the Mediterranean region, with somewhat concave margin of the siliculae, but the sepals are not pinkish and petals not so small.

Seeds contain about 15-20% oil.

This species is used as a vegetable and in the treatment of eye diseases and dysentery. It is the second most common weed on Earth.

Annual or biennial, up to 45 cm tall, erect, glabrous or hairy with simple or branched hairs. Basal leaves rosulate, very variable, usually pinnatifid (lyrate to almost entire), 5-8-jugate, shortly stalked, usually up to 8 cm long, 2 cm broad; cauline leaves smaller, sessile. ± auricled and clasping the stem. Racemes many flowered, up to 30 cm long in fruit. Flowers c. 2.5 mm across, white; pedicels up to 18 mm long in fruit, spreading. Sepals c. 1.5 mm long, l mm broad. Petals c. 2.5 mm long, 1 mm broad, obovate-oblong, cuneate. Stamens c. 1.5: 2 mm long. Siliculae obcordate- triangular, 5-9 mm long, 4-6 mm broad; valves usually with straight margins; apical notch wide, V-shaped ; style c. 0.5 mm long, hardly or not exceeding the notch; septum c. 1 mm broad, seeds 6-12 in each locule, c. 1 mm long, oblong-elliptic, pale brown.

Herbs (2-)10-50(-70) cm tall, sparsely to densely pubescent with sessile, 3-5-rayed stellate trichomes often mixed near base of plant with much longer simple trichomes. Stems erect, simple or branched. Basal leaves rosulate; petiole 0.5-4(-6) cm; leaf blade oblong or oblanceolate, (0.5-)1.5-10(-15) × 0.2-2.5(-5) cm, base cuneate or attenuate, margin pinnatisect, pinnatifid, runcinate, lyrate, dentate, repand, or entire, apex acute or acuminate. Cauline leaves sessile, sagittate, amplexicaul, or rarely auriculate, narrowly oblong, lanceolate, or linear, 1-5.5 (-8) cm × 1-15(-20) mm, margin entire or dentate. Fruiting pedicels (0.3-)0.5-1.5(-2) cm, divaricate, usually straight, slender, glabrous. Sepals green or reddish, oblong, 1.5-2 × 0.7-1 mm, margin membranous. Petals white, rarely pinkish or yellowish, obovate, (1.5-)2-4(-5) × 1-1.5 mm. Filaments white, 1-2 mm; anthers ovate, to 0.5 mm. Fruit (3-)4-9(-10) × (2-)3-7(-9) mm, flat, base cuneate, apex emarginate or truncate; valves with subparallel lateral veins, glabrous; style 0.2-0.7 mm. Seeds brown, oblong, 0.9-1.1 × 0.4-0.6 mm. Fl. and fr. Apr-Jul. 2n = 16, 32*.

Widely distributed in temperate regions.

Distribution: Cosmopolitan in cooler climates mostly.

1800-4500 m

Fl. Per.: March June.

Roadsides, gardens, fields, waste areas, mountain slopes. Throughout China [native to SW Asia and Europe; naturalized elsewhere as a cosmopolitan weed].

Thlaspi bursa-pastoris Linnaeus, Sp. Pl. 2: 647. 1753; for more than 250 synonyms, see Index Kewensis.