Wednesday, April 27, 2011

Coyote Ridge - Wildflower Hotspot #1

As you travel on Highway 101 between San Jose and Morgan Hill, you may have noticed bright patches of spring color on the hills to the east - this is Coyote Ridge.  Serpentine rock, part of our unique California fault-shaped geology, forms Coyote Ridge and soil high in some minerals and low in plant nutrients.  Some California plants have evolved to be tolerant of these conditions.

Poor soils often make for good wildflowers.  Coyote Ridge supports a colorful spring bloom of wildflowers including more than a dozen rare species.  It is also one of the few remaining habitats for the threatened bay checkerspot butterfly (Euphydryas editha bayensis) which is dependent on a few small native plant species for adult nectar and caterpillar forage.  Increased deposition of nitrogen from the air, probably primarily from automobile exhaust, is changing the unique soil conditions that create the serpentine grasslands and is allowing European annual grasses to spread on Coyote Ridge and outcompete the colorful native color that also supports the rare butterfly.
The Santa Clara County Open Space Authority is managing Coyote Ridge with grazing, prescribed burns, and other techniques to protect the serpentine grasslands.  This sensitive area is only open for guided hikes by reservation in April and May - see the Coyote Spring section of the Open Space Authority's website for details; if reservations are already full for this year, check back early next year.  It's worth being able to see this special area and knowing it is being protected.

Jewelflowers are oddly shaped.  They have the 4 petals arranged in a cross shape like  most plants in the mustard family (Brassicaceae, formerly known as Cruciferae referring to that cross signature), but they have an inflated sac at the bottom.  Probably something to do with insects.  I took this jewelflower photo on Mt. Thayer on May 28, 2010.
While you are on Coyote Ridge, expect to get down to fully see the "belly flowers" and the many types of insects that visit them.  Even the rock can be colorful.  Also take the time to gaze towards the ranchlands to the east where sometimes you can see reintroduced tule elk grazing on the distant grassy hills among widely spaced oaks.  It can be cool and breezy or hot at Coyote Ridge during the spring, so come prepared.

The featured flowers above are cream cups (Platystemon californicus) photographed by David Tharp and most beautiful jewelflower (Streptanthus albidus ssp. peramoenus) by Stephen Rosenthal.  David is an Open Space Technician with the Open Space Authority, and spends his time controlling non-native invasive plants at Coyote Ridge and monitoring the results to determine the best way to protect these natural areas in a changing human environment.  He is also an accomplished photographer and many of his photos, including those taken via wildlife cameras, are featured on the Open Space Authority website.  Especially see the Sightings section of their website.

"The most beautiful jewelflower" is indeed that flower's real name and it is a strong indicator of serpentine soils.  Stephen took the jewelflower photo at the top on Coyote Ridge on April 10, 2010.  See more of his photos of Coyote Ridge and other natural areas here.

So, who is the Edith that the checkerspot butterflies are named after?

This post is part of a series of Wildflower Hotspots in the Santa Cruz Mountains of the central coast of California.

*** Next up is Wildflower Hotspot #2 - Edgewood County Park.  I got a hot tip tonight that it is going to look fabulous this weekend - so go soon! Here is a sneak-peak link to their docent-led hikes.***

See also:
Coyote Ridge, Santa Clara County Open Space Authority


  1. That jewelflower is neat looking. Always enjoy reading your posts.

  2. Wow Cindy! Thanks for the story it is much more than I expected. I can’t wait to see the remaining places. We live in a spectacular area. DT

  3. What fun! Looking forward to reading all the rest of the installments, and hopefully finding out about new places to hike!


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