A flower of hollyhock, Alcea rosea. The picture shows a flower that has been open for some days, and illustrates protandry. Both male and female parts
A flower of hollyhock, Alcea rosea. The picture shows a flower that has been open for some days, and illustrates protandry. Both male and female parts of the flower are visible; the feathery column (white) is a mass of stamens, each terminating in an open anther that has shed its pollen. The bundle of vertical red rods amidst the anthers (above picture centre) are styles, each terminating in a female receptive surface, the stigma. The small white spherical particles visible on the stigmas are pollen grains, probably from a different flower. The flower is hermaphrodite, but the male and female organs mature at different times (so-called dichogamy); in this species the male first (protandry). Protandry is widespread, particularly in insect-pollinated species. It evolved in order to favour, though it does not guarantee, cross-pollination within plants with hermaphrodite flowers.
Size: 3468px × 5212px
Photo credit: © DR JEREMY BURGESS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: alcea, anther, cross, dichogamy, flower, garden, hermaphrodite, hollyhock, plant, pollen, pollination, protandry, rosea, stamen, stigma, style
