Type of inflorescence in which all pedicles (floral stalks) eradiate from a common point. E.g., geranium, gardenia. One can also say the umbel is a raceme whose axis did not elongate: the younger flowers are in the center and the older gradually distal. (Also see Raceme, Inflorescence).
Undulated
Leaf or petal with wavy margin. The term is not applied to serrated or toothed margins.
Unisexual
Monoecious or Dioecious plants in which the flower are male or female; flower that is not hermaphroditic, but is either male or female. (compare with Hermaphrodite).
Corm: Subterranean organ for storage, with a thick stalk covered by a thin paper-textured layer. At the top of the corm, a bud produces roots and shoots; type of subterranean stem similar to a bulb but without fleshy scales. E.g., Gladioli
