Ipê

''Handroanthus'' is a genus of flowering plants in the family Bignoniaceae.David J. Mabberley. 2008. ''Mabberley's Plant-Book'' third edition (2008). Cambridge University Press: UK. It consists of 30 species of trees, known in Latin America by the common names poui, pau d'arco, or ipê. The latter sometimes appears as epay or simply ipe (unaccented) in English. The large timber species are sometimes called lapacho or guayacan, but these names are more properly applied to the species '' Handroanthus lapacho'' and '' Handroanthus guayacan'', respectively.

The name ''Handroanthus'' was established in 1970,''Handroanthus'' in International Plant Names Index. (see ''External links'' below). but was not generally accepted. In 1992, its species were included in ''Tabebuia'' in the most recent revision of that genus.Alwyn H. Gentry. 1992. "Bignoniaceae: Part II (Tribe Tecomeae)". ''Flora Neotropica'' Monograph 25(part 2):1-150. ''Handroanthus'' was resurrected in 2007 when a comparison of DNA sequences by cladistic methods showed that ''Tabebuia'', as then circumscribed, was not monophyletic.Susan O. Grose and Richard G. Olmstead. 2007. "Evolution of a Charismatic Neotropical Clade: Molecular Phylogeny of ''Tabebuia'' s.l., Crescentieae, and Allied Genera (Bignoniaceae)". ''Systematic Botany'' 32(3):650-659.Susan O. Grose and Richard G. Olmstead. 2007. "Taxonomic Revisions in the Polyphyletic Genus ''Tabebuia'' s.l. (Bignoniaceae)". ''Systematic Botany'' 32(3):660-670.

''Handroanthus'' are indigenous from Central America to northern Argentina, Paraguay, Brazil, and Chile, with one species, ''Handroanthus billbergii'', native to northern South America and the Antilles. ''Handroanthus'' are frequently cultivated far from their natural range, as ornamental trees, for their large and showy flowers. They easily become naturalized where introduced because their seeds are prolifically produced and widely scattered by the wind.George W. Staples and Derral R. Herbst. 2005. "A Tropical Garden Flora" Bishop Museum Press: Honolulu, HI, USA. Several species are important timber trees of the American tropics.Alwyn H. Gentry. 1992. "A Synopsis of Bignoniaceae Ethnobotany and Economic Botany". ''Annals of the Missouri Botanical Garden'' 79(1):53-64. Medicinal use has been reported, but its efficacy and side effects have not been well studied.

Species

Species include:

* '' Handroanthus albus'' (Cham.) Mattos
* ''Handroanthus billbergii'' (Bureau & K.Schum.) S.O.Grose
* '' Handroanthus chrysanthus'' ( Jacq.) S.O.Grose
* '' Handroanthus chrysotrichus'' (Mart. ex DC.) Mattos    
* '' Handroanthus guayacan'' ( Seem.) S.O.Grose
* '' Handroanthus heptaphyllus'' ( Vell.) Mattos
* '' Handroanthus impetiginosus'' (Mart. ex DC.) Mattos
* '' Handroanthus incanus'' ( A.H.Gentry) S.O.Grose
* '' Handroanthus lapacho'' (K.Schum.) S.O.Grose
* '' Handroanthus ochraceus'' (Cham.) Mattos
* ''Handroanthus serratifolius'' ( Vahl) S.O.Grose
* '' Handroanthus subtilis'' ( Sprague & Sandwith) S.O.Grose
* '' Handroanthus umbellatus'' ( Sond.) Mattos
* '' Handroanthus vellosoi'' ( Toledo) Mattos

Description

The following description is excerpted from the paper that resurrected ''Handroanthus'' in 2007.

* Trees or occasionally shrubs.
* Wood is very dense. Heartwood distinct from sapwood, olive brown to black, lapachol present in large quantities.
* Leaves palmately (3)5-9_ foliate.
* Leaflets with various types of trichomes as well as lepidote scales.
* Inflorescence with dichotomous branching.
* Calyx coriaceous, campanulate, 5 dentate, pubescent.
* Corolla tubular, yellow or magenta with yellow throat.
* Stamens didynamous; Thecae divaricate; Staminode reduced.
* Ovary conical to linear, bilocular.
* Ovules in 2 to 10 series in each locule.
* Fruit an elongate dehiscent capsule.
* Seeds thin with 2 wings. Wings thin and sharply demarcated from seed body.

''Handroanthus'' is distinguished from ''Tabebuia'' by several morphological characters. The wood is among the hardest and heaviest known. The heartwood is distinct from the sapwood and contains large quantities of lapachol. ''Handroanthus'' has the same lepidote scales as ''Tabebuia'', but also has various types of hair. The calyx is 5-dentate and campanulate to cupular. The corolla is yellow, except in those four species where it is magenta with a yellow throat. ''Tabebuia'' has only two yellow-flowered species, ''Tabebuia aurea'' and '' Tabebuia nodosa''. The fruit of ''Handroanthus'' is rarely glabrous like that of ''Tabebuia''. It usually ranges from sparsely pubescent to densely tomentose.

Uses

''Handroanthus'' is widely used as an ornamental tree in the tropics in landscaping gardens, public squares, and boulevards due to its impressive and colorful flowering. Many flowers appear on still-leafless stems at the end of the dry season, making the floral display more conspicuous. '' Handroanthus impetiginosus'', '' Handroanthus chrysotrichus'', and '' Handroanthus ochraceus'' are well-known throughout the tropics. '' Handroanthus chrysanthus'', '' Handroanthus guayacan'', ''Handroanthus serratifolius'', '' Handroanthus umbellatus'', and '' Handroanthus vellosoi'' are also planted in warm climates.Anthony Huxley, Mark Griffiths, and Margot Levy (1992). ''The New Royal Horticultural Society Dictionary of Gardening''. The Macmillan Press, Limited: London. The Stockton Press: New York. (set).

'' Handroanthus heptaphyllus'', ''Handroanthus serratifolius'', ''Handroanthus guayacan'', ''Handroanthus chrysanthus'', and ''Handroanthus billbergii'' are important timber trees of the Neotropics. The wood of ''Handroanthus billbergii'' is valued for carving. Indigenous peoples of the Amazon made hunting bows from the wood, which is the source of the common name ''pau d'arco'', "bow stick".

Much of the lumber from ''Handroanthus'' is exported. The wood is durable outdoors, where it is usually used for furniture and decking. It is increasingly popular as a decking material due to its insect resistance and durability. ''Handroanthus'' and the unrelated ''Guaiacum) produce the hardest, heaviest, and most durable wood of the American tropics. Dead trees of ''Handroanthus guayacan'' remain standing after they were killed by flooding of their habitat during construction of the Panama Canal.

The wood of ''Handroanthus'' brings a high price. The wood of other species is sometimes fraudulently sold as ''Handroanthus''. By 2007, FSC-certified ipê wood had become readily available on the market, although certificates are occasionally forged.

Much of the ipê imported into the United States is used for decking. Starting in the late 1960s, importing companies targeted large boardwalk projects to sell ipê, beginning with the New York City Department of Parks and Recreation, which maintains the city's boardwalks, including along the beach of Coney Island. The city began using ipê around that time and has since converted the entire boardwalk—over long—to ipê. The ipê lasted about 25 years, at which time (1994) the department began replacing it with new ipê. '' La Sultana'', a yacht refashioned from a Soviet spy vessel, was fitted with an ipê deck during its restoration.La Sultana Superyacht: The Spy Ship You Can Sunbathe On
Billionaire. 14 September 2015. Tara Loader Wilkinson. 24 December 2015. In 2008-2009, Wildwood, New Jersey, rebuilt a section of its boardwalk using ipê. The town had pledged to use domestic black locust, but it was not available in time.

Given that ipê trees typically grow in densities of only one or two trees per , large areas of forest must be searched and cut down to create paths to harvest the trees to fill orders for boardwalks and to a lesser extent, homeowner decks.

The bark of several species of ''Handroanthus'' is sold in South American markets. Similar-looking bark is often fraudulently passed off as ''Handroanthus''. It is used in various ways to relieve certain symptoms of certain cancers. No evidence shows that it prevents the disease or slows its progression, as is often claimed.

The bark is dried, shredded, and then boiled to make a bitter or sour-tasting brownish-colored tea. Tea from the inner bark of pink ipê ('' Handroanthus impetiginosus'') is known as pau d'arco, lapacho, or taheebo.

'' Handroanthus ochraceus'' (synonym: ''Tabebuia heteropoda''), '' Handroanthus incanus'', and other species are occasionally used as an additive to the entheogenic drink Ayahuasca.Jonathan Ott. 1995. In: Ayahuasca Analogues: Pangaean Entheogens.

Ecology

The nectar of ''Handroanthus'' flowers is an important food source for several species of bees and hummingbirds.

'' Mycosphaerella tabebuiae'', a plant pathogenic sac fungus was first discovered on a ''Handroanthus'' tree, known at that time as ''Tabebuia''. The taxonomy of Mycosphaerella is in much confusion and the recognition of this name is questionable.

Symbolism

Because of its popularity, ''Handroanthus'' has often been adopted as a symbol or emblem for nations or other political divisions.

The distinction between national flower and national tree is sometimes not entirely clear. Gentry (1992) gives the following information without making that distinction.

* Brazil - ''Handroanthus serratifolius''
* Ecuador - ''Handroanthus chrysanthus''
* Paraguay - ''Handroanthus heptaphyllus''
* Venezuela - ''Handroanthus billbergii''

History

The genus ''Handroanthus'' was erected by Joáo Rodrigues de Mattos in 1970.Joáo Rodrigues de Mattos. 1970. "''Handroanthus'', Um novo gênero para os "ipês" do Brasil". ''Loefgrenia'' 50: 1-4. It was named for the Brazilian botanist Oswaldo Handro. "Anthus" is derived from a Greek word for "flower".

Most botanists at that time did not agree with the separation of ''Handroanthus'' from ''Tabebuia''. Alwyn H. Gentry objected strenuously and warned against "succumbing to further paroxysms of unwarranted splitting".Alwyn H. Gentry. 1972. "''Handroanthus'' (Bignoniaceae): A critique". ''Taxon'' 21(1):113-114.

In 1992, Gentry published a full taxonomic treatment of ''Tabebuia'', in which he described 99 species and one hybrid for the genus. These consist of the 67 species and one hybrid that remain in ''Tabebuia'', the two species transferred to '' Roseodendron'', and the 30 species that are now placed in ''Handroanthus''. Gentry divided ''Tabebuia'' into 10 species groups. ''Handroanthus'', as it is currently circumscribed, is composed of Gentry's groups 3, 4, and 5. Gentry believed group 5 to be natural, while groups 3 and 4 were artificial, designated for the sole purpose of easier identification.

In 2007, a molecular phylogenetic study resolved ''Tabebuia'' as consisting of three strongly supported clades, none of which was sister to either of the others. Thus ''Tabebuia'' was shown to be polyphyletic. One of these clades consisted of the two species that constitute the genus '' Roseodendron''. Another contained the type species for ''Tabebuia'', and consequently retained that name. The name ''Handroanthus'' was resurrected for the third clade, which contained its type species, '' Handroanthus albus''.

''Handroanthus'' is sister to a clade consisting of '' Spirotecoma'', ''Parmentiera'', ''Crescentia'', and '' Amphitecna''. It had for a long time been placed in the tribe Tecomeae, but that tribe has been greatly reduced to only 11 or 12 genera and no longer includes ''Handroanthus''. ''Handroanthus'' is one of the 12 to 14 genera that make up a group informally known as the ''Tabebuia'' alliance.Richard G. Olmstead, Michelle L. Zjhra, Lúcia G. Lohmann, Susan O. Grose, and Andrew J. Eckert. 2009. "A molecular phylogeny and classification of Bignoniaceae". ''American Journal of Botany'' 96(9): 1731–1743. This group has not been assigned to any taxonomic rank, and neither has Crescentiina, the smallest group that it is a member of.

Cladistic analysis of DNA data has strongly supported ''Handroanthus'', but sampling of taxa and DNA has not been sufficient to strongly support any relationships within the genus.

References

{{Taxonbar, from=Q5647550

Bignoniaceae genera