Datura gives arid elegance

As the last hint of spring cool vanishes, white trumpets begin to stud the roads and dry washes of the West. They are large and amazingly fragile upon a dark-mounded plant quite common in this brutal climate. A nightshade of world renowned, wild datura is popping up in drought-stricken gardens of the West, flowering like a gift from nature. Formerly maligned as weeds, the great white trumpets are welcome elegance in a rugged dry garden.

Those unaware of datura’s sordid history may not know that the gift has a dark side. Datura contains powerful alkaloids used in folk medicine and ritual everywhere it grows. What every apothecary learns is the fine line between medicine and poison, and datura walks a literal tight rope. It is no mystery why this is often the only green herbaceous plant because wildlife dare not touch it.

WARNING: Datura is toxic to human beings and pets. Avoid use where kids and animals share the space. In addition, avoid pruning or handling leaves without protection. The alkaloids are able to enter the skin while pores are open for sweating and may result in trans-dermal poisoning.

In the 19th century, datura’s alkaloids were harnessed for asthmatics, who smoked the foliage to improve lung function. However, the plant is notoriously unpredictable in its alkaloid content depending on where and how it is cultivated. It’s also rather toxic to administer this way, not to mention lung damage that resulted. To meet demand for Materia Medica, many similar species were imported from around the world to test and breed. These eventually escaped to naturalize. This is why so many species found wild across the U.S. are of unknown origin due to their global antiquity.

Big hummingbird moths flock to datura flowers at dusk. Their enormously long tongues venture deep into the nectaries of the flowers for which they are perfectly adapted to pollinate. Often they are seen resting on blooms at dawn, satiated and ready to sleep out the day. Here females lay their eggs on the undersides of the leaves. They soon hatch into large hungry larvae similar to tomato hornworms that are voracious feeders easily controlled by BT.

Pollinated flowers develop golf ball-sized seed pods studded with wickedly sharp spines, lending yet another common name, thorn apple. Mature seed lies within dry pods where it’s easy to gather from local plants for planting in home gardens. Daturas grow easily from seed sown directly into garden soil on mounds, in rock gardens, on slopes and drainage ditches. This demonstrates a preference for lean, fast-draining ground. It’s also one of the few plants that share the same water and soil demands as succulents and cactus so it’s a valuable accent there.

Datura is often confused with the tropical South American brugmansia hybrids, which are visually similar and bear the same common name, angel’s trumpet. The chief difference between them for identification is orientation of the flower. Brugmansias hang downward, while datura remains forever upright and open to her pollinating moths.

The most useful of the hybrids to gardeners in ordinary climates is the exotic double purple datura with its shiny black stems. This is a tall, black stem fast-growing seasonal plant that is perennial in the tropics but typically sown from seed as an annual elsewhere. This is an outstanding plant for modern and exotic settings that won’t demand a boat load of water. Many general seed catalogs carry this variety with some websites devoted exclusively to its diversity.

The Southwestern species Datura inoxia is a true native species used by many tribes for ritual and medicine and the most drought-tolerant. Its ethnobotanical use in divination was detailed in a ’60s classic read, “The Teachings of Don Juan: A Yaqui Way of Knowledge.” Take note of where they choose to grow close to your home, then mark your calendar to return summer’s end to gather seeds.

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Maureen Gilmer is an author, horticulturist and landscape designer. Learn more at www.MoPlants.com