A new species of lichen blew down out of the canopy.  I think it might have been growing in a cherry tree.  I never see this species anywhere near eye level.  I've only seen it once before, and that was another twig blown down by the wind.  It turns out to be ragged lichen, Platismatia glauca.  Thanks to Richard Droker for providing the identity.  He is an amazing photographer, and I aspire to improve my photography to his level.  Before asking Richard for the identity of this lichen, I tried to look it up myself in my gigantic book of lichens.  My hand gets tired holding this book while I try find the species.  I would like to find the species the correct way, by using the key, but the key in this book asks for the results of chemical tests I don't yet know how to perform.  Lichens of North America is a beautiful book.

Lichens are symbiotic even more so than most plants and animals.  Humans are symbiotic in many senses.  We have hundreds of species of bacteria in and on our bodies, keeping our systems in balance, and the loss of those bacterial species can lead to poor health.  Lichens are more thoroughly symbiotic in that they are composed of two species, a fungal host and an algae growing inside.  The algae growing in these lichens can exist outside their hosts, but they look and act very different.  There are about 18,000 known species of lichen, combining different fungal bodies with different algae inside.  The fungus provides a home for the alga, keeping it moist and providing certain minerals.  The photosynthesis taking place in the algae provides energy for growth in the fungal body.  It is similar in a way to the mitochondria in the human body that provide the energy we need to live.  Mitochondria have their own genomes, separate from the DNA that defines a person.  We would die with mitochondria. 

In fact, humans are ecosystems in and of themselves.  Over 200 species of bacteria live on the skin of the average human.  If I counted those bacteria, and I was able to photograph and document them, they would get me most of the way to my goal of 365 species for the year.  You have more cells in and on your body of a different species than you have cells with your own DNA.  Your personal cells with your DNA are typically larger, and most of your body mass is made up of your cells.  Still, if you took away all the other species from your own little ecosystem, you would die instantly.  Much of the diversity of species has been removed from Eagle Landing Park and may never come back.  My goal in improving the health of ELP is to get ride of the invasive, cancerous species of plants, and increase the diversity of native plants.  I can't bring back grizzly bears and elk, unfortunately.  The one invasive species that will never go away is humans, but hopefully they can be converted from parasitic to symbiotic in nature.