Capsella bursa-pastoris (L.) Medik.

Shepherd's Purse

Capsella bursa-pastoris plant

Family - Brassicaceae

Habit - Taprooted annual forb.

Stem - Weakly ascending to erect, to 70 cm, often multiple from base, sometimes sparsely branched, pubsecent with sessile stellate, stalked forked, and simple hairs, mostly toward the base.

Capsella_bursa-pastoris_stem.jpgStem and nodes.

Leaves - Basal and alternate. Basal leaves numerous, petiolate, the blades oblanceolate, irregularly toothed and/or pinnatifid. Stem leaves relatively few, reduced upward, mostly sessile and clasping with prominent auricles, lanceolate to linear, entire or shallowly toothed or lobed, pubescence as with basal leaves.

Capsella_bursa-pastoris_basals2.jpgBasal leaves.

Capsella_bursa-pastoris_leaf1.jpgLeaf adaxial.

Capsella_bursa-pastoris_leaf2.jpgLeaf abaxial.

Capsella_bursa-pastoris_auricle.jpgAuricle with branched hairs.

Inflorescences - Terminal racemes, greatly elongating in fruit, the lower branches sometimes subtended by reduced leaves.

Capsella_bursa-pastoris_inflorescence2.jpgInflorescence.

Flowers - Sepals 4, 1-2 mm long, ascending, elliptic, usually sparsely pubescent, sometimes with white or reddish purple margins. Petals 4, 2-4 mm long, not lobed, white. Styles 0.2-0.7 mm long. Stamens 6, with 2 shorter than other 4. Ovary 1 per flower, superior, of 2 fused carpels, usually with 2 locules. Style 1 per flower, persistent in the fruits, the stigma 1, entire. Ovules numerous.

Capsella_bursa-pastoris_calyces.jpgCalyces.

Capsella_bursa-pastoris_flowers.jpgFlowers.

Fruits - Silicles, spreading to ascending, 4-8 mm long, about as long as wide, obtriangular, flattened at a right angle to the septum, the tip usually slightly concave, dehiscing longitudinally, each valve with a network of nerves. Seeds 8-20 in each locule, 0.8-1.1 mm long, oblong in outline, the surface with a fine, netlike or honeycomb-like pattern of ridges and pits, orangish yellow

Capsella_bursa-pastoris_fruits.jpgFruits.

Flowering - January - December.

Habitat - Pastures, fields, lawns, roadsides, railroads, nearly any open, disturbed area.

Origin - Native to Eurasia.

Lookalikes - Thlaspi arvense, several species of Lepidium.

Other info. - This is one of the earlier plants to flower in spring, and in fact can be found blooming sporadically at any month of the year. It is extremely common, and is probably present in every county of Missouri and every state of the U.S. Although there are several lookalikes, this species can be positively identified by its unique triangular fruits.

The fecundity of this plant is due to several factors. The flowers are partially self-fertile, the plants continue to bloom for an extended period of time, and a single plant can produce up to 90,000 seeds. Furthermore, the seeds produce a mucilaginous substance when wet, which glues them to passing animals and aids in their dispersal. Young leaves and fruits are edible and a good source of Vitamin C. The plant also has a long history of medicinal use, though controlled studies demonstrating significant benefits are lacking. The name "shepherd's purse" derives from the resemblance of the fruits to leather bags once used by shepherds to carry their food into the fields.

Photographs taken in Washington, Franklin County, MO, 4-26-2018 (SRTurner).



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