×''Chitalpa'' is an intergeneric hybrid flowering tree in the family

Bignoniaceae Bignoniaceae () is a Family (biology), family of flowering plants in the Order (biology), order Lamiales commonly known as the bignonias or trumpet vines.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant ...

. There are two major forms in North America, the 'Morning Cloud' a hybrid of desert willow (''

Chilopsis linearis ''Chilopsis'' is a monotypic genus of flowering plants containing the single species ''Chilopsis linearis''. It is known commonly as desert willow

'') for desert hardiness and color, and northern catalpa (''

Catalpa speciosa ''Catalpa speciosa'', commonly known as the northern catalpa, hardy catalpa, western catalpa, cigar tree or catawba, is a species of ''Catalpa'' native to the midwestern United States. The Latin specific epithet ''speciosa'' means "showy". Desc ...

''), and the 'Pink Dawn' variety formed as a hybrid of desert willow and either yellow catalpa (''

Catalpa ovata ''Catalpa ovata'', the yellow catalpa or Chinese catalpa (), is a pod-bearing tree native to China. Compared to ''C. speciosa'', it is much smaller, typically reaching heights between . The inflorescences form bunches of creamy white flowers wi ...

'') or northern catalpa (''

''). Both forms were originally thought to be hybrids of desert willow and southern catalpa (''

Catalpa bignonioides ''Catalpa bignonioides'' is a short-lived species of ''Catalpa'' that is native to the southeastern United States in Alabama, Florida, Georgia, Louisiana, and Mississippi. Common names include southern catalpa, cigartree, and Indian bean tree It ...

''). The name is nothogeneric, or a combination of the two parents' names. Leaves are

lanceolate The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...

, long and wide, almost always in whorls of three. The trumpet-shaped flowers are long and frilly.Brenzel, Kathleen N. 1997 Sunset Western Garden Book, Chitalpa entry. Sunset Publishing Corp., Menlo Park, 1997. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

is indeterminate, with alternately arranged flowers.

Cultivation

× ''Chitalpa'' is dry-spell tolerant and fast-growing (some meters or several feet a year to ) and blooms between late spring and late fall. Mountain Valley Growers: Chitalpa tashkentensis 'Pink Dawn'
/ref> Cultivars include: 'Pink Dawn' with pink flowers, 'Morning Cloud' with white and pale pink blooms, and a recent addition, "Summer Bells Minsum." It a deciduous tree, branching readily near its base and with ascending branches that form a dense, broad oval crown. It is also highly drought-resistant, a trait inherited from the desert willow. Chitalpa are also carriers of the ''

Xylella fastidiosa ''Xylella fastidiosa'' is an aerobic, Gram-negative bacterium of the genus ''Xylella''. It is a plant pathogen, that grows in the water transport tissues of plants ( xylem vessels) and is transmitted exclusively by xylem sap-feeding insects suc ...

'' bacterium.

History

The two types of trees called ''Chitalpa'' were created as hybrids by A. Rusanov of the Botanic Garden of the Uzbek Academy of Sciences in

Uzbekistan , image_flag = Flag of Uzbekistan.svg , image_coat = Emblem of Uzbekistan.svg , symbol_type = Emblem of Uzbekistan, Emblem , national_anthem = "State Anthem of Uzbekistan, State Anthem of the Republ ...

(then part of the

Soviet Union The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

) in 1964.David L. Morgan: Chitalpa Trees – Bred for the Desert, on Learn2Grow site
/ref> They were introduced in the US by Robert Hebb of the New York Botanic Garden in 1977. Unbeknownst to the scientist, the Chilopsis used for the hybrid was infected with the bacterial plant pathogen ''Xylella fastidiosa''. Due to the fact that all Chitalpas today were bred from the original root stock, all species have the pathogen. Hebb brought cuttings of two clones and grew them at the Cary Arboretum in Millbrook, N.Y. The cuttings began to flower in the third growing season, showing two color forms. These two forms were distributed in 1982, and all living plants of this intergeneric hybrid in North America are believed to have originated from this single introduction. Although the two forms were later shown to be distinct crosses in Rusanov's experiments, they are both called 'Chitalpa', as Thomas Elias and Walter Wisura from the Rancho Santa Ana Botanic garden created the name and applied it to both types in 1991.Thomas Elias: Chitalpas, in 'Pacific Horticulture', Winter 1991
/ref> The tree is ideally suited to most soils and climates of the southwestern United States.

References

External links

{{DEFAULTSORT:Chitalpa Bignoniaceae Bignoniaceae genera Garden plants Drought-tolerant trees Ornamental trees Plant nothogenera Monotypic Lamiales genera