Brugmansia

Brugmansia is a genus of seven species of flowering plants in the family Solanaceae. They are woody trees or shrubs, with pendulous flowers, and have no spines on their fruit. Their large, fragrant flowers give them their common name of angel's trumpets, a name sometimes used for the closely related genus Datura. (Datura differ from Brugmansia in that they are herbaceous perennials, with erect or nodding, rather than pendulous, flowers - and usually spiny fruit). Brugmansia species are amongst the most toxic of ornamental plants, containing as they do tropane alkaloids of the type responsible also for the toxicity of the infamous deadly nightshade. All seven species are known only in cultivation or as escapes from cultivation, and no wild plants have ever been confirmed. They are therefore listed as Extinct in the Wild by the IUCN Red List, although they are popular ornamental plants and still exist wild outside their native range as introduced species. It is suspected that their extinction in the wild is due to the extinction of some animal which previously dispersed the seeds, with human cultivation having ensured the genus's continued survival. Brugmansia are large shrubs or small trees, with semi-woody, often many-branched trunks. They can reach heights of 3–11 m (10–36 ft). The leaves are alternately arranged along the stems, generally large, 10–30 cm (4–12 in) long and 4–18 cm (2–7 in) across, with an entire or coarsely toothed margin, and are often covered with fine hairs. The name 'angel's trumpet' refers to the large, pendulous, trumpet-shaped flowers, 14–50 cm (6–20 in) long and 10–35 cm (4–14 in) across at the opening. They come in shades of white, yellow, pink, orange, green, or red. Most have a strong, pleasing fragrance that is most noticeable in the evening. Flowers may be single, double, or more. Linnaeus first classified these plants as part of Datura with his 1753 description of Datura arborea. Then in 1805, C. H. Persoon transferred them into a separate genus, Brugmansia, named for Dutch naturalist Sebald Justinus Brugmans. For another 168 years, various authors placed them back and forth between the genera of Brugmansia and Datura, until in 1973, with his detailed comparison of morphological differences, T.E. Lockwood settled them as separate genera, where they have stayed unchallenged since. Currently, there are 7 recognized species: These species are then divided into two natural, genetically isolated groups. Brugmansia section Brugmansia (the warm-growing group) includes the species aurea, insignis, sauveolens, and versicolor. Brugmansia section Sphaerocarpium (the cold group) includes the species arborea, sanguinea, and vulcanicola. Two of these species were challenged by Lockwood in his 1973 doctoral thesis.First, Brugmansia vulcanicola was said to be a subspecies of B. sanguinea, but this was refuted by Lockwood's former mentor, R. E. Schultes in 1977.Second, Lockwood proposed that the species B. insignis was instead a hybrid of the combination (B. suaveolens x B. versicolor) x B. suaveolens. This was later disproved by crossbreeding experiments done by the Preissels, published in 1997. Brugmansia are native to tropical regions of South America, along the Andes from Venezuela to northern Chile, and also in south-eastern Brazil. They are grown as ornamental container plants worldwide, and have become naturalized in isolated tropical areas around the globe, including within North America, Africa, Australia, and Asia.