Page:An introduction to physiological and systematical botany (1st edition).djvu/266

 l236, an Umbel, for which some authors retain the obsolete old English name of Rundle. In this several flower-stalks, or rays, nearly equal in length, spread from one common centre, their summits forming a level, convex, or even globose surface, more rarely a concave one. When each ray is simple and single-flowered, it is called a simple umbel, as those of Allium ursinum, ''Engl. Bot. t. 122, Ivy, t. 1267, Primula veris, t. 5, farinosa, t. 6, elatior, t. 513, and Eucalyptus , Exot. Bot. t.'' 84. In a compound umbel each ray or stalk mostly bears an umbellula, or partial umbel, as Athamanta Libanotis, ''Engl. Bot. t.'' 138. This is usually the case in the very natural order of plants called umbelliferous, to which the last-mentioned, as well as the common Carrot, Parsnep, Parsley, Hemlock, &c. belongs.

A few only of this order have simple umbels, as Hydrocotyle vulgaris, t. 751, and the curious Astrantiæ and Eriocaliæ, ''Exot. Bot. t.'' 76—79. In Euphorbia the umbel is differently compounded, consisting of