Plant Profile: Jimsonweed (Datura wrightii)

When it comes to choosing topics to write on, I generally let the seasons dictate.  A walk outside reveals a host of ideas, and most often I like to write in keeping with current happenings in the natural cycle of seasons.  Hence, the autumn months ought to be filled with information on migrating Monarchs, colorful leaves and the fall salmon run.  But at other times, an older photo jogs a memory or a book sparks an idea and I'll find myself reminiscing about the springtime desert in the fall, or summer in the Sierra during the depths of winter.  At still other times, a topic might not be as far-fetched as it may seem.

Wildflowers, you might think, fall exclusively into the territory of spring and summer but that's not quite so, as California's mild Mediterranean climate tends to defy expectation.  With the start of what is supposed to be California's rainy season, autumn rather than spring marks the beginning of our growing season.  Hillsides that have lain golden and dormant during the long, dry summer (the real "winter" for plants here) begin to sprout with new growth: summer-dormant shrubs awaken and wildflower seeds in the dry earth begin to stir.  The seasons in California are effectively reversed, with a long, hot dormant period during the summer, and the "spring" growing season beginning in autumn.  Here in our Mediterranean climate, wildflowers come and go as they please, with something pleasant blooming at all months of the year.

And so it is that we find the dazzling white trumpet flowers of Jimsonweed (Datura wrightii) carpeting wasteland areas across the state, blooming continuously from early spring through late fall.  This oft-maligned plant is generally relegated to the realm of "weeds," but is in fact a native of California and the southwest.  It has a way of making the most of things, as all weeds do, and thriving in the most unlikely of places.  Look for Jimsonweed blooming along roadsides and other neglected places throughout much of the state (except maybe in the Sierra and northern mountains). Jimsonweed is at home on a variety of soil types from sand to clay and gets by on little water.

In honor of its exquisitely beautiful flowers, D. wrightii is also known by the names Angel's Trumpet and Moon Lily.  Jimsonweed is in the nightshade family (Solanaceae) along with our familiar garden tomatoes and potatoes.  But be aware that all parts of the Jimsonweed plant are potentially lethal if ingested, as suggested by still other common names: Devil's Trumpet, Deadly Nightshade and Locoweed.  During religious ceremonies, native people of the southwest used the plant for its narcotic properties, earning it the moniker Sacred Datura.  The moral of the story: admire the flowers, but don't get too friendly; perhaps it is best to leave the flowers for the pollinators! 

At night, Datura flowers are visited by Hawk Moths and Sphinx Moths of the family Sphingidae.  The larvae of these moths, known to gardeners as tomato hornworms, might be familiar to you.  It's best to leave these critters alone though, as the agricultural application of pesticides has reduced the numbers of hawk and sphinx months, meaning there are fewer pollinators out there to pollinate neat desert plants like the Queen of the Night cactus and our new friend, Sacred Datura.

If you're interested, a more detailed article on Sacred Datura can be found here:
https://www.desertusa.com/flowers/datura-jimson-weed.html