When I first saw this shrub in Guanica, I was struck with how beautiful it was; I had no idea how interesting the ecology would turn out to be.
I love the unusual color of these flowers. It is a rich maroonish-pink, with a silvery sheen that gives the flowers a velvety appearance. That silver sheen continues onto the vegetation.
Upon closer investigation of the floral structure, I saw these three petaloid appendages, which I first took to be modified anthers (I had foolishly left my hand lens at home and did not have a microscope available with me at this stage of the trip. These things make a big difference). I really did not have a clue as to what family this plant belonged in. Those of you familiar with the flora of the western US, may recognize some of the characteristics of this plant, as there are Krameria sp. throughout the western US.
It turns out that Krameria is the only genus in the family Krameriaceae, and there are only apporximately 19 - 25 species in that genus. So not a family you learn in a botany class in Missouri.
What about the cool ecology? Two things have peaked my interest.
(1) These plants are hemiparasitic.
(2) Those petaloid structures aren't modified anthers, but modified petals that are called elaiophores. Elaiophores contain oil-secreting glands that produce oil as rewards for pollinators. (I just found all of this out yesterday, and I am pretty jazzed about it). I haven't found out much yet, like - what are the bees using the oil for. Other species of are pollinated by Centris bees. I found one vague reference to these bees using the oil to provision their nests. Are any of our resident bee experts familiar with this genus of bees?
Friday, August 28, 2009