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Capsella
bursa-pastoris (L.) Medik.
Standardized Common
Name: Shepherd’s
Purse
Family: Brassicaceae
(Cruciferae)
Taxonomy: Capsella
includes about five species of small, weedy herbs. Capsella bursa-pastoris
is a cosmopolitan, variable complex within which literally hundreds of
subspecies, varieties, microspecies, and so forth have been described. Its
appearance has been shown to vary greatly in response to environmental factors,
complicating attempts to name regional variants.
Description: Annual herb. Stem
erect, occasionally branched, 30–40(–80) cm high. Leaves in basal rosette and
alternate on stem; basal leaves petiolate, 5–7(–15) cm long, oblanceolate,
pinnatifid or entire, margins ciliate; cauline leaves few, small, sessile, with
bases clasping and auriculate; sparsely pubescent, some hairs stellately
branched. Inflorescences racemose, with long pedicels. Flowers 2–3 mm across;
sepals 4, <2 mm long, pale green to reddish, often sparsely pubescent; petals
4, white, 2–3 mm long; stamens 6, 2 shorter. Fruit a silicle, 4–10 mm long and
broad, obcordate to triangular, flattened, pale green to yellow-green,
glabrous, shiny, 2-loculed with replum running from notch to base; seeds
reddish-brown, 10–12 per locule.
Parts
in Commerce:
Whole herb (including stems, leaves, flowers and fruits)
Identification:
- Stem <3 mm
thick, terete to angled, grooved, glabrous or sparsely pubescent on lower
part
- Most leaves in
basal rosette, oblanceolate, 5–7(–15) cm long, pinnatifid to entire, with
pubescent margins
- Stem leaves few,
small, with clasping auriculate bases, sparsely pubescent
- Inflorescence
racemose
- Fruit a silicle,
green, flattened, 4–10 mm long, heart-shaped to triangular; apex broad,
notched, with rounded corners
- Petals 4,
usually 2–3 mm long, about twice as long as sepals, not <2 or >4 mm
long
- Petals white,
not yellowish, not with red margin
- Odor weak,
unpleasant
- Taste weak,
salty and astringent
Adulterants: Adulteration is not typically seen; the fruit shape is distinctive and
easily identifies the genus. In theory, European material might be contaminated
with at least two other species. Capsella orientalis Klokov has a
densely hairy stem and yellowish petals; C. grandiflora Boiss. is larger
and has larger flowers. The support for treating plants with short, red-tinged
petals as C. rubella Reut. rather than C. bursa-pastoris is
doubtful (although that treatment is accepted here).
References:
Aksoy A, Hale WHG, Dixon JM. Towards a simplified
taxonomy of Capsella bursa-pastoris (L.) Medik. (Brassicaceae). Watsonia.
1999;22:243–250.
British Herbal Medicine
Association. British Herbal Pharmacopoeia. BHMA; 1996:169.
Chater AO. Capsella. In: Tutin TG, Heywood VH, Burges NA, et al.,
eds. Flora Europaea. 2nd ed., vol. 1. Cambridge:
Cambridge University Press; 1993:381–382.
Figure 15: a–c, Capsella
bursa-pastoris fruits, inflorescence and habit.
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