Iochroma

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Solanales

Familia: Solanaceae
Subfamilia: Solanoideae
Tribus: Physaleae
Subtribus: Iochrominae
Genus: Iochroma
Species: I. albianthum – I. amicorum – I. arborescens – I. ayabacense – I. barbozae – I. baumii – I. brevistamineum – I. cachicadanum – I. calycinum – I. coccineum – I. confertiflorum – I. cornifolium – I. cyaneum – I. edule – I. ellipticum – I. fuchsioides – I. gesnerioides – I. lehmannii – I. lilacinum – I. longipes – I. loxensis – I. lyciifolium – I. mionei – I. nitidum – I. ortizianthum – I. parvifolium – I. peruvianum – I. piuranum – I. richardianthum – I. rubicalyx – I. salpoanum – I. schjellerupii – I. smithianum – I. solanifolium – I. squamosum – I. stenanthum – I. tingoanum – I. tupayachianum – I. viridescens – I. warscewiczii
Name

Iochroma Benth., Edwards's Bot. Reg. 31: t. 20. 1845. nom. cons.

Type species: Iochroma cyaneum Depends on accepted species epithet?

Synonyms

Heterotypic
Acnistus Schott
Chaenesthes Miers
Cleochroma Miers
Codochonia Dunal
Diplukion Raf. nom. rej.
Ephaiola Raf.
Eplateia Raf.
Pederlea Raf.
Valteta Raf. nom. rej.

References

Bentham, G. 1845. Edwards's Bot. Reg. 31: t. 20.
Govaerts, R. et al. 2020. Iochroma in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published on the internet. Accessed: 2020 Oct. 31. Reference page.
International Plant Names Index. 2020. Iochroma. Published online. Accessed: Oct. 31 2020.
Smith, S.D. & Baum, D.A. 2006. Phylogenetics of the florally diverse Andean clade Iochrominae (Solanaceae). American Journal of Botany 93(8): 1140-1153. DOI: 10.3732/ajb.93.8.1140 Open access Reference page.
Tropicos.org 2020. Iochroma. Missouri Botanical Garden. Published on the internet. Accessed: 2020 Oct. 31.

Vernacular names
svenska: Violbusksläktet

Iochroma is a genus of about 34 species of shrubs and small trees belonging to the nightshade family Solanaceae. They are 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.[1][2]

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.[3] 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.[4] A variety of withanolides [5] and hydroxycinnamic acid amides [6] 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.[1][2]

Species

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.
Iochroma australe. Cultivated plant, growing at UBC Botanical Garden, British Columbia.
Iochroma arborescens.
Iochroma umbellatum at University of California Botanical Garden
Iochroma cyaneum Quinta do Palheiro Ferreiro, Funchal, Madeira.
The Ecuadorian species Iochroma calycinum syn. I. macrocalyx. Temperate House, Kew Gardens.
The unresolved Mexican species Iochroma coccinea growing in the Temperate House at Kew Gardens.

The genus is currently divided into three sections.
The Ecuadorian Iochroma grandiflorum.

Section Iochroma

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

Section Lehmannia

Iochroma ellipticum (Hook.f.) Hunziker
Iochroma lehmannii Bitter

Section Spinosa

Iochroma parvifolium (Roemer & Schultes) D’Arcy (see notes)

Unclassified

Iochroma warscewiczii Regel

Notes on taxonomy

Iochroma ellipticum
Iochroma confertiflorum
Iochroma edule
Iochroma salpoanum
Iochroma peruvianum

show a marked similarity to the monotypic Acnistus and I. confertiflorum is suspected to hybridise with Acnistus arborescens in the wild.

Iochroma australe is not an Iochroma but an Eriolarynx. Occurring in Bolivia and Argentina, this is the southernmost species of Iochroma and its removal from the genus affects the geographic range as indicated above.

The plant formerly known as Iochroma cardenasianum is neither an Iochroma nor even a member of the tribe Physaleae (in which Iochroma is placed) but has been found to belong instead to the tribe Datureae. The new genus Trompettia was created to accommodate it. Within tribe Datureae, Trompettia is more closely allied to Brugmansia than to Datura.

Iochroma parviflorum is not an Iochroma but a Dunalia.
Cultivation

In cultivation in the UK, Iochroma australe has gained the Royal Horticultural Society’s Award of Garden Merit.[7][8]

Several forms of Iochroma (some wild collected, some garden hybrids) have been given cultivar names. Some of the cultivars have been assigned to species but others, mainly hybrids, have not. There may be some synonymy in this list.[9]

Iochroma australe 'Andean Snow'
Iochroma australe 'Bill Evans'
Iochroma australe 'Sunrise'
Iochroma calycinum 'Vlasta’s Surprise'
Iochroma cyaneum 'Album'
Iochroma cyaneum 'Apricot Belle'
Iochroma cyaneum 'Indigo'
Iochroma cyaneum 'Karl Hartweg'
Iochroma cyaneum 'John Miers'
Iochroma cyaneum 'Royal Blue'
Iochroma cyaneum 'Royal Queen' = I. cyaneum 'Indigo'
Iochroma cyaneum 'Sky King'
Iochroma cyaneum 'Trebah'
Iochroma cyaneum 'Woodcote White'
Iochroma gesnerioides 'Coccineum'
Iochroma gesnerioides var. flavum
Iochroma 'Ashcott Red'
Iochroma 'Burgundy Bells'
Iochroma 'Frosty Plum'
Iochroma 'Ilie’s Plum'
Iochroma 'Plum Beauty'
Iochroma 'Plum Delight'
Iochroma 'Purple Haze'
Iochroma 'Ruby Red' (I. cyaneum 'Royal Blue' x I. 'Sunset')
Iochroma 'Sunset'
Iochroma 'Wine Red'

References

Armando T. Hunziker: The Genera of Solanaceae. A.R.G. Gantner Verlag K.G., Ruggell, Liechtenstein 2001. ISBN 3-904144-77-4 pps. 220-226
De Witt, S. and Baum, David A. 2006. Phylogenetics of the Florally Diverse Andean Clade Iochrominae ( Solanaceae ) American Journal of Botany 93(8): 1140–1153.
Christopher Brickell ( Ed.), The Royal Horticultural Society Encyclopedia of Garden Plants, pub. Dorking Kindersley 1996 ISBN 0-7513-0303-8, pps. 554–555.
Schultes, R. E. and Hoffman, A. (1992). Plants of the Gods. Their sacred, healing and hallucinogenic powers. Healing Arts Press, Rochester, Vermont. p. 46.
Alfonso, D., Bernardinelli, G. and Kapetanidis, I. (1993). Withanolides from Iochroma coccineum. Phytochemistry 34 (2) : 517–521.
Sattar, E. A., Glasl, H., Nahrstedt, A., Hilal, S. H., Zaki, A. Y. and El Zalabani, S. M. H. (1990). Hydroxycinnamic acid amides from Iochroma cyaneum. Phytochemistry 29 (12) : 3931–3933.
"RHS Plantfinder - Iochroma australe". Retrieved 12 March 2018.
"AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 52. Retrieved 2 March 2018.

Shaw, J. M. H. (1998) A Review of Iochroma in Cultivation. New Plantsman 5(3): 154–192.

External links

Constantine, D. R. (2008): Iochroma - an annotated list of the species and cultivars [1]