corymb

CORYMB, n. [L. Gr.] Primarily, a top, head or cluster. In modern botany, a species of inflorescence, in which the lesser or partial flower-stalks are produced along the common stalk on both sides, and though of unequal length, rise to the same height, so as to form an even surface; as in spiraea opulifolia, scurvy-grass, &c.