top of page

August 9,2018

Dear Skyliners,

     In the last week, we've been chasing down more odds'n'ends in the weed department.  Besides our great workday with Annie's volunteers, we've worked more on Scattergrass in the Bay Grove, and mustard all along the trail and ridge.  It feels great to be buttoning down all these places.

This week, we'll be out just on Sunday, the usual time: 9:30 at Siesta Gate.  Please let me know if you can make it.

As we've been walking the Skyline Trail in the last month, we've been stopping to look at the Yampah (Perideridia kellogii) patch just south of Diablo Bend.  They are blooming now.  We call this grassy swale the Yampah Bowl, as it's where they grow best at Skyline Gardens.  Yampah is a member of the Parsley family (Apiaceae) of plants.  This family often has ferny leaves and white flowers in umbels (think the spokes of an umbrella).  The family includes Lace Plant/Cow Parsnip, Hemlock, carrots, dill, and Anise/Fennel.  In our area, Yampah (it's an Indian word) grows on east-trending, grassy slopes, where they often make good patches.  They are perennials, and one of reasons I love them is that they bloom in the midst of the dry season, and I find that heroic.  Here's a photo of the patch; the flowers stand on stalks two to three feet tall:

Perideridia kellogii yampah.jpg

The clusters of flowers are very distinctive, and when you see them, stop and look around, for Yampah is a good marker for biodiversity.  (Photo thanks to Cynthia)

Each species of butterfly (and moth) has very particular plants - called larval food plants - that their caterpillars must eat.   In the case of the Parsley Swallowtail, these plants are Parsley family.  Yampah is one of the principal native food plants for them, and you can usually find the caterpillars this time of year.  Here's a couple that we have been watching molt and grow for the last several weeks:

Parsley swallowtail inchworms.jpg

Look at those beauties, all dressed up in green, black, and yellow.  These are in their final stage of caterpillar-dom, and will soon make a chrysalis. (Photo thanks to Cynthia)

Here's a picture of an adult Parsley Swallowtail (Papilio zelicaon):

Parsley Swallowtail Papilio zelicaon.jpg

They are large, showy butterflies, with wingspans of around four inches.  The Parsley Swallowtail has a black border that surrounds the central yellow of the wings.  These are sometimes called Anise Swallowtails, because they are often found on the non-native Anise or wild Fennel, but I find that name misleading, because they were growing on the native parsleys long before Anise came over from Europe.  

We have two other fairly common yellow-and-black Swallowtails in the area, and here's a side-by-side comparison of all three:

Parsley Swallowtail Papilio zelicaon.jpg

Parsley Swallowtail

Western Tiger Swallowtail Papilio  rutul

Western Tiger Swallowtail

Pale Swallowtail (Papilio eurymedon).jpg

Pale Swallowtail

The one at the left is our Parsley Swallowtail, with the black border.  The one in the center is the Western Tiger Swallowtail (Papilio  rutulus), which has black 'tiger stripes' running through the yellow wings, and a black border only on the hindwings. They are more riparian, and their larval food plants are willows, alders, maples and such.  The one at the right is our Pale Swallowtail (Papilio eurymedon), which looks much like the Tiger Swallowtail, except that the wings are pale, the color of the moon.  They tend to be a chaparral species, as their larval food plants are in the Buckthorn (Rhamnaceae) Family which includes Coffeeberrry and Ceanothus.  (Photos above and from left: Peter Prehn of iNat; Calibas Wikipedia; and eurymedon Wikipedia).

All three of these species are Westerners - living in western North America. We often find all three 'hilltopping' at Barberry Peak.  Butterflies tend to congregate on peaks and ridges to find mates, the peaks and ridges being like a butterfly 'singles bar.  Well, why not - adult butterflies don't have chewing mouthparts; they just have a tube for nectar and fluids.  Their job is just to eat and mate.  They may have invented 'sex, drugs, and rock'n'roll'.  

The caterpillars of most butterflies (and insects) go through five different molts, or instars.  In the case of our Parsley Swallotail, each instar looks quite different.  So lets hop through the stages of growth, starting with an egg:

Parsley swallowtail egg.jpg

Here's an egg of the Parsley Swallowtail.  They are laid singly, and are a translucent yellow green.  I saw at least one egg being laid on the Yampah patch at Skyline this year, and it's a real thrill to watch.  The butterfly lands and curls her abdomen like a question mark and dabs her egg right on the leaf. (Photo thanks to Ken-ichi of iNat).

In the first two instars, the caterpillars are mostly black with a white spot, and look a lot like lady bug larvae:

first instar of parsley swallowtail cate

This one is probably the second instar.  (Photo by icosahedron of iNat).

The third to fifth instars look a lot like the lovely banded caterpillars shown above.  When they get nice and fat and are about the size of your little finger, they go off, attach themselves to a branch or rock, and transform into a chrysalis, like this:

Pale swallowtail chrysalis.jpg

First, they attach their lower 'legs' to a stalk by means of a dab of caterpillar glue, called a cremaster.  Then, they attach a silken chord to the stem and fling the chord back and forth around their 'shoulders' back and forth, each time fastening it to the stem.  When done, the chord looks like a little strand of dental floss, and you can see it in the picture. (Photo Michele Roman of iNat).

Once all is secure, the caterpillar leans back like a telephone lineman, rests, and sheds the colorful skin for a neutral brown that looks for all the world like a stub of a twig.  If these are summer caterpillars, they will stay in chrysalis until next spring, when they emerge as adults to start the cycle over.  If you have Yampah in your garden, this should be a caution about removing all those dead flower stalks, as that is often where they attach the chrysalis.  I learned this lesson the hard way.  Ideas of a tidy garden don't really mesh with a garden for wildlife.

Yampah is a great plant for the native garden; tough, long-lived, drought resistant, and full of drama.  The Swallowtails will find them, every year, like magic; I've seen it time and time again.  It's an ancient relationship and they know just what to do.

Happy Trails,


bottom of page