Carduus
(the Latin name used by Virgil, &c.). Thistle. ORD. Compositae. Hardy annuals, biennials, or perennials. Receptacle bristly; involucre tumid, imbricated with spinous bracts; pappus hairs rough, in many series, united by a ring at the base, and deciduous; corollas all tubular, and generally spreading, so as to form a hemispherical head. They are of easy culture in any common soil. None, however, are worth growing in ordinary gardens; but for massing in woods, or in the wild garden, some may be desirable. Hence, we mention the names of a few of the more conspicuous species: acicularis, Candollei, chrysacanthus, nutans, pycnocephalus (Blessed Thistle), &c. Two Compositae frequently met with in gardens, viz., Silybum Marianum and Cnicus benedictus, are often mentioned in books and catalogues under the generic name of Carduus.