Sanguisorba L.
(D.R.G., C.J.W.)
Perennial herbs, often arising from thick, branching rhizomes. Lvs alternate, mostly in basal rosettes, imparipinnate; leaflets serrate; stipules persistent, adnate to petiole for lower ⅔. Fls in dense terminal clusters or spikes, subtended by several bracteoles, ⚥ or unisexual, 4-merous, small, sessile. Hypanthium deeply concave. Epicalyx 0. Sepals greenish or purplish. Petals 0. Stamens 4-numerous. Ovary superior, surrounded by the hypanthium; carpels 1-2-(3); styles terminal and filiform; ovules solitary. Fr. of 1-(several) achenes enclosed in hardened, dry, 4-angled, sometimes ± flattened or cup-like hypanthium with variously sculptured faces and sometimes thickened or winged angles.
c. 12 spp., chiefly N. temperate. Naturalised sp. 1.
As circumscribed here the genus includes Poterium L. as sect. Poterium, to which the sole N.Z. naturalised sp. belongs. Sect. Poterium is distinguished by having at least some fls unisexual, numerous stamens, 3-colporate pollen, and fr. with hairy, wrinkled or verrucose surfaces. Holub, J., Folia Geobot. Phytotax. 11: 78 (1976), strongly argued for reinstatement of Poterium as a distinct genus. The delineation of taxa here follows Proctor, C. F. and Nordberg, G., in Fl. Europ. 2 (1968).
