Capsella bursa-pastoris Seeds | Shepherd Purse Bursa Pastoris
LATIN NAME: Capsella bursa-pastoris
COMMON NAME: Shepherd’s Purse
Plant Profile
The name is the best opening because the fruit is unforgettable. Each slender stem tops its white four-petalled flower with a flat, triangular to heart-shaped seed pod that looks exactly like the leather pouch a shepherd once carried at the belt. That little purse, botanical name bursa-pastoris, is the mark you will never confuse with any other weed in the bed.
The plant forms a low rosette of deeply lobed, feathery leaves, then throws a leafless spike of many small white flowers that keeps opening from the base up. In mild climates it blooms almost every month of the year and runs through several generations in a single season.
Unlike many mustards it is strongly self-fertile, so a single plant sets full seed without a neighbour, and the long raceme keeps adding flowers while the lowest pods already ripen. That combination is why one casual plant becomes a permanent resident of the bed.
Shepherd’s purse wears two hats. The young leaves are eaten as a potherb across East Asia, where it is a recognised green in China and Japan, while the whole herb has a long folk role as a styptic to check bleeding.
The seed too has a place in traditional Chinese practice as a diuretic and astringent, ground and taken as a powder, so the whole plant — leaf, herb, and seed — is put to use rather than wasted.
In China the plant, ji cai, is steamed, stir-fried, or folded into dumplings, and in Japan it is a spring green. The flavour is stronger than spinach and the bite is the glucosinolate talking.
The astringent herb was taken as a tea or pressed poultice to slow bleeding, leaning on the tannins and the mucilage. The action is mild and external-first, which is the safe way to meet this plant.
Science & Biotechnology
Capsella bursa-pastoris is an allohexaploid, carrying the combined genomes of parent species, and it sits in the same tribe as Arabidopsis thaliana. Geneticists use its relative Capsella rubella to study the shift to selfing, which makes this humble weed a quiet model plant in comparative genomics.
Beyond the mustard oils, the leaves and stems carry flavonoids such as rutin and quercetin glycosides, the compounds analysts report when they profile the herb. They sit alongside the tannins that give the old styptic use its bite.
Uses & Benefits
Like its cabbage-family kin, the plant makes glucosinolates, chief among them sinigrin, which release the pungent mustard-oil snap when a leaf is chewed or crushed. That bite is the defence and the flavour at once, and it is why the green tastes peppery rather than bland.
The glucosinolate mix is milder than that of horseradish or mustard, which is why the green is edible in quantity where those relatives are not; the snap is a seasoning, not a burn.
Growing from Seed
The tiny seeds carry a mucilaginous coat that swells in water, which helps them stick to soil and may explain the old use of the seed as a soothing bulk. The coat is the reason a spoonful of seed turns slimy in a glass.
The seed is dust-fine and wants only a press into the surface of moist, open ground. It needs light, not cover, and it comes up almost anywhere the soil is bare and the weather mild. Sow in spring or again in late summer for a winter green, since the plant is frost-hardy once up.
Best sown where it will stand, in a cool open drill, because the taproot resents moving. Thin the thread-like seedlings by height once they show their first true pair, and let the rest self-sow.
Sow a short row every few weeks through the cool season for a steady pick of young leaves, since the plant is frost-hardy once up and the rosette stays tender in cold weather.
Left alone, the plant seeds itself from one mild month to the next and fills gaps you did not plant. Pull the excess or welcome the green; either way it asks nothing of you but bare soil.
Our Take
I grow shepherd’s purse for the purse pods and the dumpling green, and I keep it out of the lawn on purpose. For more Brassicaceae subjects in the same bed, the Arugula seed gives the mustard bite as a crop, the Wallflower Cheiranthus cheiri brings the scented bloom, and the Rapeseed seed Brassica napus is the field-scale cousin.
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