Perennial herbs, with odd-pinnate, stipulate leaves, and small, perfect and imperfect flowers in dense heads. Calyx-tube 4-angled, constricted at the throat, 4-lobed. Petals 4. Perfect flowers with several or numerous declined stamens, the filaments capillary. Pistils 2; style terminal; stigmas brush-like. Achene enclosed in the thickened, 4-angled calyx-tube. Seed suspended. [Greek, goblet or beaker.]

About four species, natives of the Old World, the following typical.

1. Poterium Sanguisórba L. Salad Burnet

Fig. 2266

Poterium Sanguisorba L. Sp. Pl. 994. 1753. Sanguisorba minor Scop. Fl. Carn. Ed. 2, 1: no.

1772. Sanguisorba Sanguisorba Britton, Mem. Torr. Club 5: 189. 1894.

Glabrous or pubescent, erect, slender, perennial, branched, 10'-20' high. Stipules usually small, laciniate; leaflets 7-19, ovate or broadly oval, deeply incised, short-stalked or sessile, 6"-10" long; flowers greenish, in dense peduncled globose-ovoid heads, 3"-6" long, the lower ones perfect or staminate, the upper pistillate; stamens 12 or more, drooping; stigmas purple; calyx-lobes ovate, acute or acutish; fruit 1"-2" long.

In dry or rocky soil and in ballast, southern Ontario, Maine, New York and Pennsylvania to Maryland. Naturalized or adventive from Europe and native also of Asia. Summer. Garden-burnet. Blood-wort. Bibernel. Pimpernelle. Toper's-plant.