Thursday, July 30, 2009

Nature's Garden

As we approach late summer, you are likely noticing the bounty of fruits that are becoming plentiful on the plants in the Hills. Just like in many home gardens, late summer and fall is the peak of productivity for many of our fruits and vegetables, including tomatoes, many berries and squashes. Some of our native plants are closely related to the cultivated species in our gardens, but are often inedible or poisonous for humans.

One example, which is very evident during this time of year, is coyote gourd. It is also known by many other common names, including coyote melon, Calabazilla, stinking gourd, Buffalo gourd, Missouri gourd, and fetid wild pumpkin. You may have noticed a “new” patch of large, grayish-green leaves growing on the ground in a grassy or shrubby area on hikes in the hills over the past few months. This is actually the coyote gourd, but it is not new – it has been dormant over the winter and spring, with its large underground root storing lots of starch as nutrients for when the vines and leaves emerge in the summer.

The scientific name of coyote gourd is Curcurbita foetidissima, which is latin for “gourd” and “evil smelling”, because the leaves smell bad. This smell is thought to be the reason why it is called coyote gourd, because supposedly a Native American story says that that coyotes urinated on the plant to make it smell bad, leaving the fruits all for themselves to eat. Apparently Native Americans would eat the seeds of coyote gourd, like many eat pumpkin seeds today. And this similarity is not coincidence, because many pumpkins, as well as many squashes found in the grocery store (zucchini, acorn squash, yellow summer squash, and spaghetti squash) are closely related to coyote gourd. They are all from the species Curcurbita pepo. When you look at the zucchini-like yellow-orange flower of the coyote gourd, its vine and leaf structure, and its fruit (the inside even smells just like a pumpkin!), it becomes more obvious that they are all related.

Another plant related to coyote gourd that is found in our Hills, as they are both in the Curcurbitaceae (gourd) family, is wild cucumber – this plant flowered and produced fruit in the spring. However, wild cucumber seeds are not edible and are actually considered to be poisonous. But apparently both wild cucumber and coyote gourd were used for medicinal purposes by Native Americans.

Keep your eyes peeled later this summer and fall, when the leaves begin to wither, leaving behind the mature, orange-colored fruits on the ground. When the fruits dries out the seeds remain inside, making them into natural rattles - that is, if they aren’t all eaten by the animals first!

Friday, July 17, 2009

Meat “bees”

While hiking the Hellman Park Trail the other day I noticed this small deer mouse (Peromyscus sp.) lying in the middle of the trail. Upon closer inspection I noticed two “meat bees” on the mouse, ripping off tiny pieces of flesh from a wound, which was likely the original source of the mouse’s death (possibly a hawk meal that slipped away?). I have “meat bees” in quotes because they are not, in fact, bees at all – rather, they are yellow jacket wasps (Vespula spp.). They are the types of wasps that have a habit of ruining a picnic or bar-be-que by attacking food persistently. These are not the same as the paper wasps (Polistes spp.) that build large hives under the eaves of houses – rather, yellow jacket wasps generally build their large hives underground such as in rodent burrows. In southern California, there are several species of yellow jacket wasps, including the native western yellow jacket (Vespula pensylvanica), shown in this photo feeding on the deer mouse. The western yellow jacket predominantly nests in abandoned burrows in hilly, natural areas, such as the Puente Hills. A similar non-native species, the German yellow jacket (V. germanica) tends to occur in more urbanized areas, preferring to build its nest off of the ground using cavities in trees or walls. The German yellow jacket became established in the northeastern U.S. in the 1970’s and reached southern California in 1991. Although yellow jackets can cause irritation at a picnic by occasionally biting or stinging, they also provide an extremely beneficial service by eliminating large numbers of other pest insects through predation. Since they are attracted to food, the best way to avoid conflicts with yellow jackets is to remove such attractants. However, if a nest is causing a true safety issue, using lure or water traps or removal of the nest by a certified professional is preferable to using pesticides, which can harm other beneficial insects.