Umbel n. (Bot.) A kind of flower cluster in which the flower stalks radiate from a common point, as in the carrot and milkweed. It is simple or compound; in the latter case, each peduncle bears another little umbel, called umbellet, or umbellule.
... with leaves lanceolate, pubescent. Flowers in a sort of umbel. Corolla like that of A. squamosa. Fruit without the plainly visible tubercles of the foregoing species, their presence being merely suggested by a sort of net ... — The Medicinal Plants of the Philippines • T. H. Pardo de Tavera