PLANTS | ANIMALS | ECOLOGY | FUNGI | GEOLOGY | GARDENING | TOOLS
MEXICAN PLANTS & ANIMALS HOME
Excerpts from Jim Conrad's
Naturalist Newsletter
from the August 15, 2010 Newsletter issued from Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO; limestone bedrock, elevation ~39m (~128ft), ~N20.676°, ~W88.569°
PROTANDROUS FLOWERS
Look at Clerodendrum speciosissimum's flowers below:
In that picture notice that the pollen-producing stamens of the flower at the lower left are bent backwards beneath the corolla, but its style (the female ovary's long, slender "neck" with pollen- receiving stigma at its end) is held straight out. But on the flower at the right, the stamens stick straight out while the pistil bends downwards.
This is a fine example of "protandrous" flowers. Protandry is a strategy that helps flowers avoid pollinating themselves. When a protandrous flower first opens, its stamens are held straight out while the style droops downward, keeping its stigma away from the stamens' pollen-shedding anthers. That's what the flower at the right is doing. Once the anthers' pollen is shed, the stamens bend backward while the style rises into position in front of the flower to receive pollen arriving on pollinators from other flowers. That's what the flower at the lower left is doing.
Pretty neat, huh? Something amazing going on right here in Pisté, Yucatán.