Jepson Prairie - Of Blow Wives and Vernal Pools

Last Saturday we visited a Jepson Prairie, a large tract of land containing giant vernal pools. Jepson Prairie is owned and managed by the Solano Land Trust. The Land Trust offers free guided tours on Saturdays. Three volunteers lead our tour. They were all experts in the unique plant and animal species that live in vernal pools.One of the guides even fished out all sorts of specimens for us to observe.

Vernal pools happen when a an impenetrable layer of clay lies a few inches under the ground surface, and you get a wet winter followed by a long dry summer, with no rain at all. The ponds form in slight depressions During the winter, and dry up in the summer.

For the plant enthusiasts, you get unique plants that evolved to grow along the edge of the pools as the pools evaporate. In the spring, as the pools evaporate, you'll see an edge of plants around the pools.


The land is so flat that even these large pools are almost never deeper than knee-deep. You could walk across the whole thing in wellington boots. However, it's better illegal to walk in the pools without a permit.

You might also see blow wives growing in the grasslands between the pools. What an amazing name for a perfectly ordinary little prairie wildflower. I have no idea how a plant could ever come into a name like that. The docent-guides were sure to point out the blow wives to us. Somehow I suspect their interest in this plant is not completely innocent.

I thought the animal species were just amazing. The pools hadn't dried out yet, and they were teeming with weird stuff. I'll start with my favorite, the tadpole shrimp.


This is a very old species. Although they are each about the size of a quarter, they look like they would like to attach themselves to your neck and suck your brains out, probably slowly and painfully. Since they evolved hundreds of millions of years before vertebrates, that would be pretty unlikely, so I guess there's really nothing much to worry about. The guide passed around a small glass bowl of these, fresh from the pool. The closer I looked,the creepier these things seemed. They were the highlight of the trip for me.

We had a similar close look at a newt of a spotted salamander. The newt looked a lot like A Japanese Anime film character called Panyo.

The Solano land trust's Flickr page has hundreds of photos. If you want a more comprehensive look, that's where you should go.

That's my story and I'm sticking to it.