Bird's Nest Fungi, Exploding Eggs, and Mushroom Soup

Yay! Today I documented the first bird's nest fungus, Cyathus sp., in the North Campus. For months, I have been looking forward to finding these fascinating, weird, and wonderful fungi. When North Campus Director Carol Bornstein told me she had found some, I immediately knew I had to blog about them.

Bird's Nest Fungi with my finger for scale.

As you can see, this fungus looks like a miniature bird's nest with oddly flattened eggs in it. Mycologists refer to them fondly as BNFs, bird's nest fungi. The "eggs" (periodoles to be geeky and precise) are actually packages containing thousands and thousands of spores. When a raindrop, or some other drop of water, hits the periodole it causes a miniature explosion. The spores are released and propelled out of the cup (some spores can be projected over six feet in this manner), and attach to a suitable substrate by means of a special sticky base.  

How'd they get here? Very likely, they hitched a ride in with a potted plant, or on the mulch we spread to suppress weeds and help keep the soil moist.

Look at those lovely periodoles!

BNF and their closely related kin – puffballs, earthstars, and stinkhorns – all belong to the group of fungi that produce their spores inside of the fruitbody. In contrast, the white button or portobello mushroom, Agaricus bisporus, that you would buy at the grocery store, produces spores on the fruitbody. Next time you are the grocery store, pick up one of these mushrooms and look underneath the cap. If the cap has opened, you will see hundreds of gills. Each of these gills is a place for hundreds of spore producing structures. Unlike BNF, these mushrooms do not need rain for their spores to spread. Instead, when the spores are ripe, they are shot into the small space between gills. Gravity then takes hold and the spore falls down towards the earth. As the spore comes into contact with the air, it is gently carried away, hopefully in the direction of a suitable susbtrate it can attach to and continue the cycle.

Woah, I can't wait to contemplate the spore's amazing journey over my next bowl of mushroom soup!

First Baby Oaks Sprout Up in the North Campus

The North Campus is the proud parent of some baby oak trees!

Baby coast live oak sheltered by wall

Carol Bornstein, our new Director of the North Campus Gardens, discovered a couple of oak saplings on one of her recent outdoor forays. The babies are coast live oaks, Quercus agrifolia, of which we recently planted several trees. We've also planted another species of oak, the Engelmann oak, Quercus engelmanni (we planted only three of this species). Both species reside in the section of the garden called the urban wilderness which is composed of several kinds of California native trees and shrubs.

This might be the mother oak!

Oak trees provide amazing habitat value, and this is the main reason we planted them. By putting in such a  sizable stand of oaks we're hoping our created wilderness will provide habitat for a whole slough of organisms rarely, if ever, seen before in Exposition Park. In just one oak tree it would be easy to find hundreds of species of associated plants and animals and thousands of individuals (think how many birds, ants, or squirrels you find in an oak tree). One species that has already shown up with our oaks, is a tiny insect called a whitefly.

Crown whitefly nymphs on oak leaf

(each nymph is only 1 millimeter long)

It was once again thanks to Carol, who was out inspecting our lovely oaks, that we discovered these small insects. At first we thought they might be a scale insect, but Brian Brown, the Museum's Curator of Entomology, identified them as crown whiteflies, Aleuroplatus coronata. As adults these small white homopterous insects (group of insects consisting of aphids, cicadas, scales, etc) fly around to find a suitable location to lay their eggs. For the crown whiteflies their plant of choice is oak. What you see in the image above are the nymphs (immature forms) of the whitefly, they have no wings but are covered with white waxy secretions that make them look like little crowns. The nymphs feed on the leaf's juices by piercing and inserting their mouthparts into the leaf. They can cause damage to the plant's health if their numbers are high enough, and they can also transmit disease organisms from one tree to another (not unlike mosquitos transmit malaria).

Go check out your local oaks and see what animals live on them!