Yes, even weeds can be interesting. Here are two examples.
First, I’ve written about the “weed seed bank” that exists in all gardens. This inventory of dormant seeds lurks in the top few inches of soil, waiting for life-giving sunlight, air and moisture.
The weed seed bank results from earlier generations of weeds that dropped their seeds under the plant, projected them a few feet away or cast them to the winds for wider distribution. Such seeds might also be brought to the garden as the undigested part of a bird’s meal, tracked in on a visitor’s clothing, or imported with a plant from a friend or the local nursery. Whatever the source, they are part of every garden.
The weed seed bank might be called simply the seed bank, because it includes wildflowers and other garden-worthy plants as well as weeds. Abandoned gardens eventually sprout their hidden wealth of weeds and wildflowers.
Weed seeds can remain in the soil, ready for germination, for several years. Gardeners are wise to use mulch to discourage the germination of weeds and help realize “low maintenance” gardening.
Dormant seeds can be amazingly long-lived under the right conditions. Earlier this year, Russian scientists reported their discovery in Siberia of seeds that a squirrel had buried in the Early Pleistocene era, about 31,800 years ago. The seeds soon were frozen in permafrost and didn’t thaw until retrieved by the research team. With great care, scientist Svetlana Yashina cared for the seeds, which germinated and produced a flowering plant and a new generation of seeds.
The plant is the Narrow-leaved Campion (Silene stenophylla), once known by mammoths and wooly rhinos. An evolved form of this plant grows today in Arctic regions. The genus Silene includes many species, including several wildflowers of Europe and elsewhere in the Northern Hemisphere.
The story of bringing this prehistoric plant into blossom raises the possibility that more plants could be recovered from frozen seeds in Siberia, the Arctic and the Yukon, and the intriguing prospect for the gardeners to grow prehistoric weeds and other plants. Examples of other specimens include the Sago Cycad (Cycas revoluta) and the Maidenhair Tree (Ginkgo biloba). Both of these plants, which are distant relatives, have fossil histories from more than 250 million years ago, and are available today as young plants.
A second example of interest in these lowly plants involves harvesting them for the dinner table. Dandelions and purslanes are only a beginning. A new cookbook, Foraged Flavor: Finding Fabulous Ingredients in Your Backyard or Farmer’s Market, by Tama Matsuoka Wong, with chef Eddy Leroux, describes many culinary and nutritional benefits of several common weeds. Ms. Wong’s website, Meadows and More, offers more details and an extensive weed identification section.
For more about the prehistoric Narrow-leaved Campion (Silene stenophylla), including pictures, browse to the article in Discover magazine.
Another interesting ancient plant is the Amborella trichopoda (no common name), which has been called “the most primitive living flowering plant.” It may be the earliest of the angiosperms: flowering plants that emerged about 130,000,000 years ago. A useful article about this plant is available on Wikipedia. This Arboretum at the University of California, Santa Cruz is the only place in the United States that is growing this plant for botanical study. For a 1999 article on the Arboretum’s work with this plant, click here.
For more information on the book, Foraged Flavor, browse to the New York Times article.
Ms. Wong’s website, Meadows and More, has a wealth of information on culinary uses of common weeds, and an extensive series of weed photographs, with expert identifications.
For identification of weeds that are common in California, visit the Weed Photo Gallery on the University of California’s Integrated Pest Management website.