''Handroanthus heptaphyllus'', commonly referred to as the pink trumpet tree or pink tab, is a

Bignoniaceae Bignoniaceae is a family of flowering plants in the order Lamiales commonly known as the bignonias or trumpetvines.Vernon H. Heywood, Richard K. Brummitt, Ole Seberg, and Alastair Culham. ''Flowering Plant Families of the World''. Firefly Book ...

tree native to tropical and subtropical regions of

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...

. It grows in the high forest watershed of the Paraná River,

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters i ...

and

Uruguay River The Uruguay River ( es, Río Uruguay, ; pt, Rio Uruguai, ) is a major river in South America. It flows from north to south and forms parts of the boundaries of Brazil, Argentina, and Uruguay, separating some of the Argentine provinces of La M ...

. It has a limited distribution, almost exclusively inhabiting low lands with wet and deep soils, where it forms part of the upper layer of tree cover. It is the national tree of Paraguay, declared as such in the Nº4631 Act of May 10, 2012, as proposed by the School of Chemical Sciences at the

National University of Asunción National may refer to: Common uses * Nation or country ** Nationality – a ''national'' is a person who is subject to a nation, regardless of whether the person has full rights as a citizen Places in the United States * National, Maryland, c ...

in celebration of the bicentenary of Paraguay's independence.

Description

''Handroanthus heptaphyllus'' can reach up to 40 m in height. The bark is brown-gray, very rough, with deep cracks in adult specimens. ''H. heptaphyllus'' requires specific light and humidity conditions, and is susceptible to frost when young. The tree is considered decorative, and is frequently used in parks, squares and public woodland. It is often confused with ''

Handroanthus impetiginosus ''Handroanthus impetiginosus'', the pink ipê, pink lapacho or pink trumpet tree, is a tree in the family Bignoniaceae, distributed throughout North, Central and South America, from northern Mexico south to northern Argentina. It is the national ...

'', which has similar characteristics except for tree height and leaf size. As per Brazilian botanist Lúcia Lohmann, ''Handroanthus heptaphyllus'' is a short-medium height tree with a maximum height of 15 m. Its leaves are palmate compound with opposite orientation. Each compound leaf contains 5-7 elliptical leaflets that are 10-15 cm long and have serrated edges. The tree is

semi-deciduous Semi-deciduous or semi-evergreen is a botanical term which refers to plants that lose their foliage for a very short period, when old leaves fall off and new foliage growth is starting. This phenomenon occurs in tropical and sub-tropical woody spe ...

with purple/pink tubular flowers that develop before the leaves. The flowers can vary in color from bright pink to pale pink or even white. The fruit of ''H. heptaphyllus'' is shaped like a long pod up to 30–40 cm long and 1-1.5 cm wide. The pods are brown when ripe and eventually open longitudinally and drop up to 150 winged seeds. It withstands high winds and has a strong and deep root system. Flowering begins in the first half of September. Approximately 30 days after flowering begins, the first leaves begin to appear. Ripe fruit appears between January and February.

Properties

The wood is hard and heavy, with noticeable differences between sapwood and heartwood. The heartwood turns a dark color with oxidation. The wood is very weatherproof. It is used in the construction of boats, docks, truck beds, beams, crosspieces, stairs, floors, as well as woodturning. Sawing produces a pale yellow sawdust containing lapachol. The wood has

tannins Tannins (or tannoids) are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids. The term ''tannin'' (from Anglo-Norman ''tanner'', f ...

and pigments. The sawdust or wood chips, bark and leaves can be used for medicinal purposes. The tree is easily propagated by seeds. The number of seeds/kg is 32,000 to 35,000. Planting should be done as quickly as possible, as the seeds will only germinate during the first 12–15 days.

Vegetative propagation Vegetative reproduction (also known as vegetative propagation, vegetative multiplication or cloning) is any form of asexual reproduction occurring in plants in which a new plant grows from a fragment or cutting of the parent plant or spec ...

through the

rootstock A rootstock is part of a plant, often an underground part, from which new above-ground growth can be produced. It could also be described as a stem with a well developed root system, to which a bud from another plant is grafted. It can refer to a ...

is also possible. In this species, certain trees produce white flowers. These "white lapachos" are often reproduced by grafting.

References

* López, J.A; Little, E; Ritz, G; Rombold, J; Hahn, W. 1987. Árboles comunes del Paraguay: Ñande yvyra mata kuera. Paraguay, Cuerpo de Paz, 425 pp. * Alwyn H. Gentry: Bignoniaceae. Part II. (Tribe Tecomeae). In: Flora Neotropica, Band 25, Teil 2. New York Botanical Garden Press, 11. April 1992. * Susan O. Grose und Richard G. Olmstead: Taxonomic Revisions in the Polyphyletic Genus Tabebuia s. l. (Bignoniaceae). In: Systematic Botany, Band 32, Heft 3, 2007. S. 660–670. {{Taxonbar, from=Q311357 heptaphyllus Trees of Paraguay Garden plants of South America Ornamental trees