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.
Late summer brings out the tough ones among plants, the ones that thrive despite going for months without rain.
Tall Flatsedge (Cyperus eragrostis)
Count this as one of the toughest. Tall Flatsedge really defies its resume by being here at all. Botanical sources describe it as a wetland plant that thrives in vernal pools, streambanks, ditches, and other wet areas. But here it is, thriving in a field of dry dead grasses. The photograph shows the plant’s flower. It isn’t much for showy display. But then it doesn’t rely exclusively on seed dispersal for reproduction. It spreads via rhizomes, like some species of bamboo. It’s native to the Western states, but has invaded many other parts of the world. It isn’t always appreciated there. Washington State lists it on its Noxious Weeds page. The Center of Agriculture and Biosciences Inernational (CABI) has it in its Invasive Species database. It’s considered an invasive weed in Australia. It has been known to infest rice fields and irrigation ditches. So while we may love our native plants, we need to accept that others may feel quite differently about them. The available online sources don’t indicate any nutritional or medical applications for this plant.
Fat Hen (Atriplex prostrata)
Fat Hen (Atriplex prostrata) is also a lover of wet areas. It’s often seen at the edges of pickleweed areas, where it gets its feet wet in salt water. It has clever hairs through which it excretes excess salt. This particular plant grows in the rip-rap on the north shore of the park. Possibly its roots go far enough to sip salt water at high tides. It appears vigorous. Its stems are thick with tiny flowers of both genders.
Its origins are obscure but probably Eurasia. It’s thought to be edible but not interesting. It’s considered an invasive weed in Australia. One source says that if you grow it alongside potatoes, it will stifle the potatoes.
Horseweed (Erigeron canadensis)
Talk about tough plants! Horseweed (Erigeron canadensis) grows in any kind of soil, even gravel, with any degree of moisture. It produces myriads of seeds from spring to autumn that float long distances on the wind and germinate on contact. Most notably, the plant has developed resistance to Roundup (glyphosate), and is the first plant to have done so. Not only glyphosate, but often also paraquat, atrazine, diuron and ALS-inhibiting herbicides. This American native plant is very hard to kill, and farmers hate it. If left unchecked, it can reduce soybean yields by more than 80 percent. It’s listed as a weed almost wherever it grows.
Before the age of industrial agriculture, on the other hand, people cultivated or collected Horseweed when they could. It provided medication to indigenous Americans for a great variety of ills. It was also a common vegetable in their diets. Traders brought it to Europe already in the 17th century. Apothecaries extracted an oil from it that was used to treat bleeding and inflammations.
What’s in a name? Despite the name, the plant is not distinctive to Canada; it’s a native all over North America. And horses, along with other livestock, won’t eat it.
Bull Thistle (Cirsium vulgare)
The Bull Thistle, like Horseweed, has its foes and its friends. Among the foes are ranchers who find this large and spiny plant occupying valuable grazing area, with zero value for livestock. It’s also among the first plants to grow in clearcut or burned-over forest, competing for resources with tree seedlings. It has deep and strong tap roots and grows fast. It can grow in any kind of soil, wet or dry. It’s a prolific seed producer and can, with favorable conditions, cover acres of ground. Once established, it’s very hard to get rid of. The California Invasive Plant Council joins numerous other organizations and jurisdictions worldwide in describing it as an invasive weed, with a “moderate” rating.
On the other hand, the Bull Thistle is a prolific producer of nectar, and is host to numerous butterflies and other pollinators. Its seeds are a favorite for goldfinches, who also use the fluff to cushion their nests. Dark-eyed Juncos also like the seeds. Small herbivorous mammals eat the leaves and stems. It has a considerable medicinal history among pre-industrial peoples. The roots, stems, leaves and seeds can be cooked and eaten as a vegetable in survival situations.