| Handroanthus | |
|---|---|
 | |
| Flowering araguaney oripê-amarelo (Handroanthus chrysanthus)Brazil | |
Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Lamiales |
| Family: | Bignoniaceae |
| Clade: | Crescentiina |
| Clade: | Tabebuia alliance |
| Genus: | Handroanthus J. R. Mattos |
| Type species | |
| Handroanthus albus (Chamisso) J. R. Mattos | |
| Species | |
30 species, see text | |
Handroanthus is agenus offlowering plants in thefamilyBignoniaceae.[1] It consists of 30species oftrees, known inLatin America by thecommon namespoui,pau d'arco, oripê. The latter sometimes appears asepay or simplyipe[pronunciation?] (unaccented) inEnglish. The largetimber species are sometimes calledlapacho orguayacan, but these names are more properly applied to the speciesHandroanthus lapacho andHandroanthus guayacan, respectively.
ThenameHandroanthus wasestablished in 1970,[2] but was not generally accepted. In 1992, its species were included inTabebuia in the most recent revision of that genus.[3]Handroanthus wasresurrected in 2007 when a comparison ofDNA sequences bycladistic methods showed thatTabebuia, as thencircumscribed, was notmonophyletic.[4][5]
Handroanthus areindigenous fromCentral America to northernArgentina,Paraguay,Brazil, andChile, with one species,Handroanthus billbergii, native to northernSouth America and theAntilles.Handroanthus are frequentlycultivated far from theirnaturalrange, asornamental trees, for their large and showy flowers. They easily becomenaturalized whereintroduced because their seeds are prolifically produced and widelyscattered by the wind.[6] Several species are important timber trees of theAmericantropics.[7]Medicinal use has been reported, but itsefficacy andside effects have not been well studied.
Species include:[8]
The following description is excerpted from thepaper that resurrectedHandroanthus in 2007.[5]
Handroanthus is distinguished fromTabebuia by severalmorphologicalcharacters. 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 asTabebuia, 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 andTabebuia nodosa. The fruit ofHandroanthus is rarelyglabrous like that ofTabebuia. It usually ranges from sparsely pubescent to denselytomentose.
Handroanthus is widely used as anornamental tree in the tropics inlandscaping gardens, public squares, and boulevards due to its impressive and colorful flowering. Many flowers appear on still-leafless stems at the end of thedry season, making thefloral display more conspicuous.Handroanthus impetiginosus,Handroanthus chrysotrichus, andHandroanthus ochraceus are well-known throughout thetropics.[6]Handroanthus chrysanthus,Handroanthus guayacan,Handroanthus serratifolius,Handroanthus umbellatus, andHandroanthus vellosoi are alsoplanted inwarm climates.[9]
Handroanthus heptaphyllus,Handroanthus serratifolius,Handroanthus guayacan,Handroanthus chrysanthus, andHandroanthus billbergii are important timber trees of theNeotropics.[7] The wood ofHandroanthus billbergii is valued forcarving.[1] Indigenous peoples of the Amazon made hunting bows from the wood, which is the source of the common namepau d'arco, "bow stick".[10]
Much of thelumber fromHandroanthus isexported. The wood is durable outdoors, where it is usually used forfurniture anddecking. It is increasingly popular as a decking material due to itsinsect resistance and durability.Handroanthus and the unrelatedGuaiacum (Zygophyllaceae) produce the hardest, heaviest, and most durable wood of the American tropics.[7] Dead trees ofHandroanthus guayacan remain standing after they were killed by flooding of theirhabitat during construction of thePanama Canal.[1]
The wood ofHandroanthus brings a highprice. The wood of other species is sometimesfraudulently sold asHandroanthus. By 2007,FSC-certified ipê wood had become readily available on the market, although certificates are occasionally forged.[11]
Much of the ipê imported into the United States is used for decking. Starting in the late 1960s,importing companies targeted largeboardwalk projects to sell ipê, beginning with theNew York City Department of Parks and Recreation, which maintains the city'sboardwalks, including along thebeach ofConey Island. The city began using ipê around that time and has since converted the entire boardwalk—over 10 mi (16 km) 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.[12] In 2008-2009,Wildwood, New Jersey, rebuilt a section of its boardwalk using ipê. The town had pledged to use domesticblack locust, but it was not available in time.[13]
Given that ipê trees typically grow indensities of only one or two trees per 1 acre (0.40 ha), large areas offorest must be searched and cut down to create paths toharvest the trees to fill orders for boardwalks and to a lesser extent, homeownerdecks.
The bark of several species ofHandroanthus is sold in South American markets. Similar-looking bark is often fraudulently passed off asHandroanthus. It is used in various ways to relieve certainsymptoms of certaincancers.[7] 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 theinner bark of pink ipê (Handroanthus impetiginosus) is known as pau d'arco,lapacho, or taheebo.[14]
Handroanthus ochraceus (synonym:Tabebuia heteropoda),Handroanthus incanus, and other species are occasionally used as anadditive to theentheogenic drinkAyahuasca.[15]
Thenectar ofHandroanthus flowers is an important food source for several species ofbees andhummingbirds.[16]
Mycosphaerella tabebuiae, aplantpathogenicsac fungus was first discovered on aHandroanthus tree, known at that time asTabebuia.[citation needed] Thetaxonomy ofMycosphaerella is in much confusion and the recognition of this name is questionable.[citation needed]
Because of its popularity,Handroanthus has often been adopted as asymbol oremblem fornations or otherpolitical divisions.
The distinction betweennational flower andnational tree is sometimes not entirely clear. Gentry (1992) gives the following information without making that distinction.[7]
The genusHandroanthus was erected byJoáo Rodrigues de Mattos in 1970.[17] It wasnamed for theBrazilianbotanistOswaldo Handro. "Anthus" isderived from aGreek word for "flower".[citation needed]
Most botanists at that time did not agree with theseparation ofHandroanthus fromTabebuia.Alwyn H. Gentry objected strenuously and warned against "succumbing to further paroxysms of unwarranted splitting".[18]
In 1992, Gentry published a fulltaxonomictreatment ofTabebuia, in which hedescribed 99 species and onehybrid for the genus.[3] These consist of the 67 species and one hybrid that remain inTabebuia, the two species transferred toRoseodendron, and the 30 species that are now placed inHandroanthus. Gentry dividedTabebuia into 10 species groups.Handroanthus, as it is currentlycircumscribed, is composed of Gentry's groups 3, 4, and 5. Gentry believed group 5 to benatural, while groups 3 and 4 were artificial, designated for the sole purpose of easieridentification.
In 2007, amolecular phylogeneticstudy resolvedTabebuia as consisting of threestrongly supportedclades, none of which wassister to either of the others.[4] ThusTabebuia was shown to bepolyphyletic. One of these clades consisted of the two species that constitute the genusRoseodendron. Another contained thetype species forTabebuia, and consequently retained thatname. ThenameHandroanthus was resurrected for the third clade, which contained itstype species,Handroanthus albus.[5]
Handroanthus is sister to a clade consisting ofSpirotecoma,Parmentiera,Crescentia, andAmphitecna. It had for a long time been placed in thetribeTecomeae, but that tribe has been greatly reduced to only 11 or 12 genera and no longer includesHandroanthus.Handroanthus is one of the 12 to 14 genera that make up agroup informally known as theTabebuia alliance.[19] This group has not been assigned to anytaxonomic rank, and neither hasCrescentiina, the smallest group that it is a member of.
Cladistic analysis ofDNA data has strongly supportedHandroanthus, but sampling of taxa and DNA has not been sufficient to strongly support any relationships within the genus.