The angiosperms underwent an adaptive radiation during the Cretaceous, and for the most part escaped the major extinctions at the end of the Cretaceous. Sterile parts of flowers are the sepals and petals . When these are similar in size and shape, they are termed tepals. Flowers may be complete, where all parts of the flower are present and functional, or incomplete, where one or more parts of the flower are absent. Others produce a stalk bearing numerous flowers, termed an inflorescence.
Many flowers show adaptations for insect pollination, bearing numerous white or yellow petals.
Others, like the grasses, oaks, and elms, are wind pollinated and have their petals reduced and often inconspicuous. Angiosperm Life Cycle Flowering plants also exhibit the typical plant alternation of generations. The dominant phase is the sporophyte, with the gametophyte being much reduced in size and wholly dependant on the sporopohyte for nutrition. The is not a unique angiosperm condition, but occurs in all seed plants as well. Life cycle of corn, a typical monocot angiosperm.