Iochroma is a genus of about 34 species of shrubs and small trees belonging to the nightshade family Solanaceae and found in the forests of South America and Mexico (- see I. coccinea below). They range from Colombia to Argentina or when certain species are excluded (see below) from Colombia to Peru. Their hummingbird-pollinated flowers are tubular or trumpet-shaped, and may be blue, purple, red, yellow, or white, becoming pulpy berries. The cupular (cup-shaped) calyx is inflated in some species. The leaves are alternate, simple, and entire.
Iochromas are cultivated as flowering ornamentals and in cooler zones (zones 7–8/9) make useful patio shrubs for summer display or conservatory plants. The majority are not frost-hardy and must be overwintered under protection. In warmer zones (zones 9–10) they can be used as landscape plants.They are commonly trained as standards (topiary) to control their size and shape. Iochroma flowers attract hummingbirds (Americas only) and bees to gardens.
Like many plants in the Solanaceae, Iochroma species contain phytochemicals with potential pharmaceutical value but the genus has not been exhaustively studied in this respect. Iochroma fuchsioides is taken by the medicine men of the Kamsa Indians of the Sibundoy valley in the Colombian Andes for difficult diagnoses, the unpleasant side effects lasting several days. A variety of withanolides and hydroxycinnamic acid amides have been isolated from Iochroma species.
Like other plant families, the Solanaceae is divided further into subfamilies, tribes and subtribes. Iochroma is in the subtribe Iochrominae along with the genera Acnistus, Dunalia, Eriolarynx, Saracha, and Vassobia. Of these, Acnistus is particularly close - to such an extent that species within the genera Iochroma and Acnistus have been known to cross in the wild, creating bigeneric hybrids.
The genus Iochroma is not completely known. Several of the species listed here are known to have resulted from hybridisation in the wild and there is extensive synonymy which is not recorded here. Recent research indicates that some of the species listed here are not Iochroma (see notes) although changes in nomenclature have not formally been published. There are also known to be undescribed species.
The Ecuadorian Iochroma grandiflorum.
Iochroma albianthum S. Leiva
Iochroma australe Grisebach (see notes)
Iochroma ayabacense S. Leiva
Iochroma calycinum Bentham
Iochroma confertiflorum (Miers) Hunziker
Iochroma cornifolium Miers
Iochroma cyaneum (Lindley) M. L. Green
Iochroma edule S. Leiva
Iochroma fuchsioides Miers
Iochroma gesnerioides (Humboldt, Bonpland & Kunth) Miers
Iochroma grandiflorum Bentham
Iochroma loxense Miers
Iochroma nitidum S. Leiva & V. Quipuscoa
Iochroma peruvianum (Dunal) J. F. Macbride
Iochroma piuram S. Leiva
Iochroma sagasteguii sp. nov ined.
Iochroma salpoanum S. Leiva & P. Lezama
Iochroma schjellerupii S. Leiva & Quipuscoa
Iochroma squamosum S. Leiva & V. Quipuscoa
Iochroma stenanthum S. Leiva, V. Quipuscoa & N. W. Sawyer
Iochroma tingoense sp. nov ined.
Iochroma tupayachianum S. Leiva
Iochroma umbellatum (Ruiz & Pavon) D'Arcy