Sunday, October 10, 2010
A Foliose Romp, Part 2
The headliner here is the backside of a sunflower leaf that was hosting what appeared to be two aphid armies preparing for battle on opposite sides of the leaf. After taking a few photos, I started to imagine the "charge" to the middle of the leaf and wish I had a video camera. Anyway, after staring at the beautiful sunflower blossoms for a while, I decided there are already enough sunflower photos circulating and, on a whim, I turned over a couple of leaves. It's always nice to "turn over a new leaf" once in a while. Not only were the aphids intriguing, but looking this close at the venation in the leaf is mesmerizing.
The next two photos, finally, are what this whole expedition was meant to be about in the first place. The lichens are essentially fungi that have developed a symbiotic relationship with algae. One of the first people to recognize this was Beatrix Potter of Peter Rabbit fame. She was a brilliant scientist at a time when men wouldn't let women into the club. We were rewarded by her next career writing childrens stories. But, what did we lose?
For ease of initial identification the lichens are placed into three groups according to overall body type. The foliose are leaf like, as in the third photo from the top. The fruticose have "stems" that terminate in prominent clusters of algae, sometimes bright red or orange, that resemble fruits. Finally, the crustose grow mostly on rocks as a thin crust that is often indistinguishable from stains or paint. A patch of crustose lichen a few inches across can be hundreds of years old. They contribute to soil making by etching away at their rocky substrates.