Monday, May 26, 2014

Jewelweed

Jewelweed
Impatiens capensis
Jewelweed has both cleistogamous and chasmogamous flowers.  Seriously, that's how botanists talk!  I think their goal is to make sure that no one knows what they're saying when they're talking dirty!!

Translation; cleistogamous = self-pollinating and chasmogamous means cross-pollination.  Anyone who's ever seen a Jewelweed is familiar with the pretty orange flowers, but if you look closer you'll see some small green closed flowers.  The small green flowers are self-pollinated and produce seeds that are clones of the parent.  While this doesn't promote adaptation, it takes less energy and is more reliable than cross-pollination.  So, this works better in degraded habitats or when the plant is stressed.  It's been noticed that when the plants are grazed, most of the regrowth only has the green flowers.

Jewelweed has more reproductive strategies than a wolf at a singles bar.  The lower lips of the flower act as guides for hummingbird beaks and as a platform for bees and other insects.  The tubular flower guides them in to the nectar and the stigmas, which hold the pollen.  The spur at the end produces copious amounts of nectar.  Hummingbirds, bees and other insects can pollinate this plant.  Most go in through the opening, but some have figured out a way to just chew a hole at the bottom and leisurely sip the nectar.

The plant can be quite tall and delicate so that it sways easily in the breeze.  One theory about this is that when a hummingbird sticks its beak in, the plant easily moves and therefore puts more pollen on the beak of the hummingbird.  Someone even did an experiment by tying supports on the plants and comparing the amount of pollen on the beaks of hummingbirds using the free, swaying plants versus the supported plants.  They found significantly more pollen from the swaying plants.

Jewelweed has gone out of its way to have a variety of pollination strategies, which is probably why I see it everywhere.



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