Arunciis dioicus, (Walter) Fernald

Tutin, T. G., Heywood, V. H., Burges, N. A., Moore, D. M., Valentine, D. H., Walters, S. M. & Webb, D. A., 1981, Flora Europaea. Volume 2. Rosaceae to Umbelliferae, Cambridge University Press : 6

1. A. dioicus (Walter) Fernald , Rhodora 41: 423 (1939).

(inch A. sylvestris Kostet , A. vulgaris Rafin. , Spiraea aruncus L. ). Rhizome stout, much branched; stems up to 2 m, simple, erect. Leaves up to 1 m, 2-pinnate; leaflets ovate, acute, cuneate to subcordate at base, acutely biserrate. Inflorescence large, pyramidal. Flowers c. 5 mm in diameter, subsessile, usually unisexual. Petals oblong- to obovate-cuneate. Fruit c. 3 mm, pendent. Damp or shady places in mountain districts. From Belgium and the Pyrenees to S. Poland, C. Ukraine and N. Albania. Al Au Be Cz Ga Ge He Hs Hu It Ju Po Rm Rs (W). Subfam. Rosoideae Stipules present, usually persistent. Flowers usually 4-, 5- or 6-merous. Hypanthium flat or concave, often with a central carpophore, sometimes campanulate or tubular; epicalyx sometimes present; stamens usually numerous, sometimes enclosed in or adnate to the hypanthium. Basic chromosome number 7, 8 or 9.