Monthly Archives: July 2011

The Milkweed Meadow

By Daniel Marlos

When I think of beautification in Elyria Canyon Park, I think of many things that can be done, but at the top of the list is the need to preserve the native habitat that exists there.  Our endangered California Black Walnut Trees immediately come to mind because there is so little natural walnut woodland remaining in California, but there are countless other micro-habitats within Elyria Canyon Park that also need attentions.  There are at least two stands of Indian Milkweed, Asclepias eriocarpa, that come up each year in the park.  One of these stands can be found on the trail that leads down into the park from Killarney Street at the bend in the road near Roseview Avenue.

Right now, in early July 2011, the milkweed is just beginning to sprout.  The tallest plants are only about a foot tall, though most are shorter.  White woolly leaves stand out dramatically against the brown hills in an area where the annual nonnative grasses have been removed during brush clearance.  In another month, the tallest Indian Milkweeds should begin blooming.

Milkweed is an important food plant for the migratory Monarch Butterflies, which take nectar from the blossoms and lay eggs on the leaves.  I have never had the luck of spotting any Monarch Caterpillars on the Indian Milkweed in Elyria Canyon Park, but each year I look nonetheless.  There are several other insects that depend upon the milkweed for survival.  Large Milkweed Bugs, bright orange and black insects, can frequently be found feeding on the fluids in the milkweed seeds.  Insects that feed on Milkweed benefit from being able to ingest the milky sap which contains alkaloids, latex and other complex compounds including cardenolides.  Some milkweeds contain toxins that the insects retain in their bodies ensuring that the insects will also be toxic, or at least unappetizing.

Insects that feed upon milkweed are often colored orange and black, colors that are considered aposematic, meaning that they are warning colors for predators.

In an effort to bring this Milkweed Meadow to the attention of hikers and other visitors to the park, I just installed a hand painted sign as an informative marker.  I hope this is just the first of several signs that can be installed throughout the park in an attempt to inform the public about our native and endangered vegetation that is easily crowded out when invasive exotic weeds and trees get a foothold in the open spaces.