BIOL 1902 Lecture Notes - Lecture 20: Caltha Palustris, Lythrum Salicaria, Staminode
12 Apr 2016
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Document Summary
Ultraviolet light allows pollinators to see colours that our eyes can"t: e. g. Cross-pollination (outbreeding) = better; greater genetic diversity. Flower w/ both sexual organs = hermaphroditic; perfect flowers. If pollen was up high and female flower is down low, pollen will fall to ground so better to have female flower on top. Which is why cones are at top of trees: spatial separation w/ each sex on separate plant (dioecious, white campion: either only male or female flowers on 1 plant. Temporal separation of the sexes: jewelweed flowers start off as males, male part falls off, & flower becomes female, temporal sex change = dichogamy. Pink lady"s-slippers employ placement strategy & also use deceit & a trap: pouch-petal has slit opening, staminode = mixer of stamens & pistils put together, both partially blocked by staminode & sticky pollen masses. Pink lady"s-slippers deceive pollinators w/ false promises: pseudopollen e. g. rose pogonia, arethusa or dragon"s mouth.
