Thanks to the contributions of two energetic people who know plants, chavezpark.org is publishing a complete botanical inventory of the park. Jutta Burger PhD is Lead Scientist for the California Invasive Plant Council, and Bob Huttar is a certified arborist and a consulting field biologist specializing in botany generally and rare plants in particular. Together they are photographing and identifying everything that grows in the park, both common and scientific names. They’ve done the scientific heavy lifting. I’m adding some background blog-talk. We’re publishing the results in a series, with a new installment every Friday.
Summer is a tough time to find new species in the park. Nature is pretty much done pushing up the year’s novelties, and the parks management has mowed huge areas down. Nevertheless, Jutta Burger persisted and has come up with three additional species. Not spectacular, not photogenic, but definitely present and entitled to be on the Chavez Park botanical census.
Salt Sand-Spurrey (Spergularia marina)
The salt sand-spurrey is a California native with a wide distribution worldwide. It tolerates salty conditions. Other than the intelligence that it provides modest value as fodder for seashore cattle in Australia, the online literature is bare. Wikipedia says nothing about the plant, but several paragraphs about botanists through the centuries who assigned it different names and ranks. It’s not toxic and it’s not threatened. It can produce rather pretty pinkish/whitish flowers in the summer, but they weren’t ready to bloom at the moment.
Lesser Swine Cress (Lepidium didymum)
Lesser Swine Cress (Lepidium didymum) is a member of the cabbage and mustard family. The origin is unknown but often laid in South America. It’s found worldwide. In some places, its leaves serve as a vegetable raw or cooked; the flavor is said to be hot and cress-like. If cows eat it, it may give their milk an off flavor. It has a long history in traditional medicine, cited for use against a great variety of ills. The most comprehensive source about it is tropicalferns.info. But you can also look it up in
Prostrate Knotweed (Polygonum aviculare)
Prostrate knotweed (Polygonum aviculare) is related to buckwheat and dock, both of which also occur in the park. It’s a very common weed thought to be native to Eurasia. Its seeds can lay dormant for many years, and only sprout when exposed to light. Because of this property it is often found in disturbed soils and in plowed fields. It has an interesting history as a foodstuff. Wikipedia says:
It formed a traditional ingredient in porridge consumed by Germanic peoples of western Europe, and has been found in numerous autopsies of peat bodies, including the Tollund Man.
The USDA Forest Service has more information:
Prostrate knotweed is reported to have many medicinal uses, including the treatment of gingivitis, cardiovascular conditions, infections, and immunity disorders (review by ). Prostrate knotweed tea has been used to treat asthma  and diarrhea . One source reports that exposure to prostrate knotweed may cause dermatitis . According to English medieval superstition, an infusion of prostrate knotweed stems and leaves could stunt the growth of young boys or animals. Such properties were recognized by Shakespeare, who referred to “knot-grass” in A Midsummer Night’s Dream: “Get you gone, you dwarf;/You minimus, of hindering knot-grass made” (review by ).
Prostrate knotweed seeds are edible to humans, either whole or ground into flour [70,98]. In China, people eat young prostrate knotweed shoots and leaves and drink prostrate knotweed tea (review by ).
Prostrate knotweed has been used in phytoremediation of soils contaminated with heavy metals  or crude oil . It may also be used in erosion control (review by ). In China, parts of prostrate knotweed are used as an insecticide to control the pear leaf weevil (Rhynchites coreanus) and to treat maggots and roundworms in pigs . Prostrate knotweed is a valued honey plant in Greece  and Australia. In China, flowering stems are used as a textile dye (review by ).