This section is from the book "An Experimental History Of The Materia Medica", by William Lewis.
Bursa Pastoris Pharm. Paris. Bursa pastoris major folio sinuato C. B. Thlaspi Bur/a Pastoris Linn. Shepherds purse: a plant with small tetrapetalous whitish flowers, along the upper part of the branches, followed each by a triangular seed vessel resembling a purse, whence its name: the lower leaves are for the most part deeply jagged like those of dandelion, and widen from the bottom forwards; those on the stalks are entire, and most of them broadest at the bottom, with a little ear on each side at the juncture with the stalk. It is annual, common in waste grounds, and flowers from April to the end of summer.
(a) La Poterie (Poterius) Pharm. spagyr. lib. i. sect. i. cap. 2.
This herb has, when fresh, an unpleasant smell, which in drying is dissipated: its taste is almost merely herbaceous. An extract made from the dry leaves by water is somewhat ungratefully mucilaginous and subsaline: an extract made by rectified spirit has somewhat more of an unpleasant, though weak, taste. No pungency or astringency could be perceived either in the leaves themselves or in the extracts; nor did a decoction of them strike any degree of blackness with solution of chalybeate vitriol. There does not appear, therefore, to be any foundation for the strong styptic virtues, for which this herb has been generally recommended by writers on the materia medica; or for the acrid inflammatory power, which some (milled probably by its botanic affinity with mustard and some other acrid vegetables) have ascribed to it.