The National Audubon Society’s “Wildflowers of North America” (Knopf, 2023) is a tour de force in the realm of plant guides. Full-page profiles of more than 850 species are included, each of which features up to six or more opulent photographic close-ups. This is a book to be savored, plant by plant, page by page. Remarkably, the $39.99 book is available through online vendors for $31, an incredible bargain if you ask me.
I was fascinated to learn that there is a California native spurge known as wild poinsettia or fire-on-the-mountain (Poinsettia cyathophora). The bracts that surround its tiny flowers are not solid red like those seen on the holiday poinsettia but red at the base and otherwise green. Snow-on-the-mountain (Poinsettia marginata) is another notable spuirge. Its tiny bracts are green in the center but surrounded by wide white margins. I once saw a manicured hedge of this species in front of a house in Atwater Village; it left an indelible impression on me.
There is a map of North America beside each plant where you learn whether it is native, introduced, or rare, depending on its location in North America. The highly recognizable fragrant water lily, for example, is native to the eastern US and Canada, rare in central Canada, and has been introduced to California and the West. “Introduced” means that, while non-native, it can be found growing in the wild and, in some cases, has been classified as invasive. For water garden enthusiasts, it is worth noting that the yellow Rocky Mountain pond lily (Nuphar polysepala) is a California native.
Speaking of water lilies, I learned from this volume that they are among the oldest plants on Earth. The Audubon Society chose to organize species according to their appearance on the evolutionary timeline and water lilies are in the first group of plants (Nymphales) presented in the book. They are followed by other moisture-loving species, proving that plant life, like that of animals, originated in an aqueous environment.
Paintbrushes (Castilleja spp) are fascinating species. They are hemiparasitic which means that although they make their own food through photosynthesis like any other plant, their roots seek out the roots of other plants; they penetrate these foreign roots, absorbing water and minerals that they find there. The roots of nearly any plant will support paintbrush growth, although plants that share their habitat, such as Artemisia species, will be the most suitable hosts. You can even grow paintbrushes in containers as long as you plant potential hosts for parasitic roots along with them.
The ubiquitous white or Dutch clover (Tifolium repens) is a Eurasian species that has been introduced throughout the US and often pops up in lawns. Trifolium repens means “three-leafed creeper,” a moniker that aptly describes its look and growth habit. We read that “the leaves and flowers of this plant, high in protein, have been used by some people as a food source.” Be take care: Upon further investigation, I found that while consuming white clover in small quantities is fine, exaggerated clover consumption can be toxic to your system.
Longing for a green carpet to cover an unplanted expanse in my backyard that was once a lawn, I scattered white clover seed last fall. I neglected the advice regarding pre-treatment of an area destined for seeding, whether you are planting grass, clover, or wildflower seed. That advice is to thoroughly soak the area and wait for weeds to emerge. After several weeks, you remove sprouted weeds and then plant your seed.
However, I did not follow this advice and scattered the clover seed without previously soaking the area, not thinking that too many weeds would appear. I was wrong and after a few weeks of watering the clover seed, the area was covered in weeds with barely any signs of clover visible. There were dandelions, sow thistle, and lesser swine weed, but predominantly chickweed. I knew, however, that clover was aggressive once it started to grow and I thought that if it ever did take off, maybe it would squelch the weeds. Well, I must report that by mid-March the clover was growing like gangbusters and was slowly engulfing the weeds, which have virtually vanished by now. I had planted the clover at the high end of the recommended rate (two pounds per thousand square feet) and, by April, it had reached six inches in height.
I really love my clover. It is lush green and will never need fertilizer because, as a legume, it makes its own nitrogen with the assistance of Rhizobium bacteria that live in its root nodules. It owes its strength to roots that grow two feet deep and stolons or runners which trail along the ground, rooting as they go. Stolons, by the way, are the structures by which Bermuda grass and strawberries propagate themselves asexually or clonally. Clover lawns have thrived in Los Angeles during the past few years of water rationing and have no problem staying lush with two weekly irrigations or less in hot weather.
The drawbacks to clover are its sensitivity to heavy foot traffic and its flowers which attract bees. However, when flowers appear, you can mow clover down to a height of three inches, which will eliminate the flowers. Keep in mind, however, that bees and other insects that visit clover can be useful in pollinating your fruit and vegetable crops. And you never need to mow clover at all if you are content with its six-inch height and gum drop-shaped white flowers. Clover stands out in being more shade tolerant than any lawn grass and not being affected by dog urine.
California native of the week: If you like yellow, scatter seeds from a packet of Hooker’s evening primrose (Oenothera elata), one of the selections on display in “Wildflowers of North America.” No plant grows more readily from seed than this biennial. I promise that if you are diligent in keeping the soil moist – from germination until seedlings grow into robust young plants – you will be richly rewarded with scads of butter-yellow blooms, growing on stems that may reach six feet in height. Although needing consistent moisture to establish itself, evening primrose is highly drought tolerant once it matures. This evening primrose, so-called since its flowers open up after midday and whither the next morning, blooms heavily all summer long and drops its seeds prolifically so that some consider it weedy, although its seedlings are easily pulled from areas where you do not want it to grow. California evening primrose (Oenothera californica) is a deciduous perennial that is not at all weedy and has the aspect of a ground cover, growing two to three feet wide but reaching a height of less than six inches.
If there are any wildflowers of note in your garden, please send your wildflower story to me at joshua@perfectplants.com where your questions, comments, and plant photos are always welcome.
Source: www.mercurynews.com