Large single flowers like this are typical of the species. Click to download a large (800x600) version of this image.
Horn-of-plenty is sometimes called downy thorn apple, but that's a poor name for this mostly glabrous (non-downy) annual. The name downy thorn apple is better used for the perennial Datura inoxia, which certainly does have downy leaves. These two species of devil's trumpets are otherwise quite similar, though. Horn-of-plenty is not as sprawling as downy thorn apple and has a more upright posture, getting 3-5 ft (1-1.5 m) tall with a regular branching pattern, like a candelabra. Whereas downy thorn apple has funnel shaped flowers with five lobes, horn-of-plenty's similar shaped flowers have ten lobes. The round, golf ball size fruit of horn-of-plenty is knobby rather than spiny as is the fruit of downy thorn apple. The foul smelling leaves of horn-of-plenty are oval in shape and up to 8 in (20 cm) long. The flowers are more or less erect, up to 7 in (20 cm) in length. Flowers come in white, yellow, purple and even blue, and many cultivars have double or triple flowers. Cultivars with purple flowers have dark purple stems; otherwise stems are green.
Steve grows the poplar purple double-flowered cultivar in a mixed flower bed. Click to download a large (800x600) version of this image.
The colorful immature seed pod of the purple double-flowered cultivar contrasts beautifully with the plant's almost black stems. Click to download a large (800x600) version of this image.
Location Datura metel is probably native to southeast Asia, including southern China and India. It has become naturalized as a roadside and waste area weed in many parts of the tropics, including Australia where it is listed as a noxious weed.
Horn-of-plenty and other members of the genus Datura are frequently encountered as weeds, and are usually quite easy to cultivate. They grow in most garden soils and do best in calcareous soils. Light: This and other devil's trumpets do best in full sun. Moisture: Provide normal garden watering for horn-of-plenty. They like a moisture retentive soil that is nevertheless well drained. Hardiness: USDA Zones 7-10. Datura metel is an annual. In cool climates, start seeds indoors and set out after the last frost. Propagation: Sow seeds in situ or in pots for a head start on the season.
Horn-of-plenty is a little scruffy looking, not particularly neat or tidy: call it a coarse textured annual. The flowers are short-lived, opening in the evening and lasting a single day, and have a pleasant fragrance only for a short while. The upside is that the plants bloom over a long period in warm weather, right up to the first frost. We grow this and other devil's and angel's trumpets as specimen plants in mixed flower beds. Horn-of-plenty is pollinated by night flying moths, especially hummingbird moths and the adult stage of the ever popular tomato hornworm.
Another favorite of gardeners is the yellow double-flowered cultivar - take a closer look, download a larger version (800x600) of this image.
Horn-of-plenty plants stand erect to about 5 ft in height with an open habit and large coarse leaves.
Horn-of-plenty has been cultivated for centuries in China and India for medicinal uses and its narcotic properties. Extracts of the leaves and seeds are used for a very wide range of ailments. However, the medicinal dose is very close to the toxic dose (see WARNINGS, below), and only qualified experts should administer this potent alkaloid factory. Scopolamine, and atropine, among other alkaloids, are contained in Datura metel leaves, flowers and seeds.
Angel's trumpets hang down, pointing from heaven; devil's trumpets point up from you-know-where.
There are eight species of Datura, and lots of other names in the literature that have been shown to be synonyms or otherwise invalid. The perennial angel trumpets with pendulous flowers, formerly included in Datura, are now placed in their own genus, Brugmansia. If you're like me and just love the angel and devil trumpets, you may want to check out the American Brugmansia and Datura Society.
All parts of horn-of-plenty (as well as the other species of Datura) are poisonous and could be fatal if ingested by humans, livestock or pets. Eating even a small amount of leaves, flowers or fruits could cause severe headache, hallucination, or even unconsciousness. Cases of deliberate poisoning have been linked to various species of Datura.
It has been suggested that the ornamental angel trumpets may act as reservoirs for viral diseases that attack other members of the Solanaceae including potatoes and tomatoes.