Bignoniaceae - WikiHQ

Bignoniaceae () is a family of flowering plants in the order Lamiales commonly known as the bignonias or trumpet vines. It is not known to which of the other families in the order it is most closely related.

Nearly all of the Bignoniaceae are woody plants, but a few are subwoody, either as vines or subshrubs. A few more are herbaceous plants of high-elevation montane habitats, in three exclusively herbaceous genera: Tourrettia, Argylia, and Incarvillea. The family includes many lianas, climbing by tendrils, by twining, or rarely, by aerial roots. The largest tribe in the family, called Bignonieae, consists mostly of lianas and is noted for its unique wood anatomy.

The family has a nearly cosmopolitan distribution, but is mostly tropical, with a few species native to the temperate zones. Its greatest diversity is in northern South America. A great many species are known in cultivation. Various other uses have been made of members of this family. Several species were of great importance to the indigenous peoples of the American tropics. Fridericia elegans, Tanaecium bilabiata, and Tanaecium excitosum are poisonous to livestock and have caused severe losses. or about 860.

thumb|Bignoniaceae in [[Bagh-e-Jinnah, Lahore]]

Description

thumb|190px|left|[[Tecomaria capensis]]

Members of this family are mostly trees or lianas, sometimes shrubs, and rarely subshrubs or herbs.

Lianas of the tribe Bignonieae have a unique vascular structure, in which phloem arms extend downward into the xylem because certain segments of the cambium cease the production of xylem at an early stage of development. The number of these arms is four or a multiple thereof, up to 32.

The leaves are petiolate. Leaf arrangement usually is opposite, or rarely alternate or verticillate (in whorls). Leaves are usually compound, bifoliate, trifoliate, pinnate, or palmate, or rarely simple. Stipules are absent, but persistent; enlarged axillary bud scales (pseudostipules) are often present. Domatia occur in some genera.

thumb|left|190px|[[Dolichandrone falcata in Hyderabad, India]]

Flowers are solitary or in inflorescences in a raceme or a helicoid or dichasial cyme. Inflorescences bear persistent or deciduous bracts or bractlets.

The flowers are hypogynous, zygomorphic, bisexual, and usually conspicuous. The calyx and corolla are distinct. The calyx is synsepalous, with five sepals. The corolla is sympetalous, with five petals, often bilabiate. Corolla lobes are imbricate in bud, or rarely valvate, and usually much shorter than the corolla tube. Stamens are inserted on the corolla tube, alternating with corolla lobes. The four stamens are didynamous, members of each pair often connivent, the adaxial stamen is usually staminodial or absent; rarely with five fertile stamens or with two fertile and three staminodial stamens. The stigma is bilobed, and usually sensitive; a style is present. The ovary is superior, usually surrounded by a nectary disk, composed of two carpels, bilocular and with a septum, except unilocular in Tourrettia and quadrilocular in Eccremocarpus. Placentation is axile, except parietal in Tourrettia. Ovules are numerous.

thumb|right|Bignoniaceae flower, upper lip removed. Notice the [[Stamen#Descriptive terms|didynamous 4 stamens and the style-stigma, all in dorsal position.]]

The fruit is usually a bivalved capsule, often with a replum. Dehiscence is septicidal or loculicidal. The three exceptions are the genera Kigelia, Crescentia and their close relatives, and Colea and its close relatives. In these, the fruit is indehiscent, not a capsule, and the seeds are not winged. The fruit is a berry in these genera. Seeds are usually flat and winged. Aril is absent. Endosperm usually absent, and sometimes sparse. Iridoids are usually present. Other compounds detected in Bignoniaceae include verbascosides, cornoside, quercetin, ursolic acid, saponins, and catalpic acid.

The chromosome number does not vary much in Bignoniaceae. The haploid (base chromosome number) is 20 for nearly every species sampled, but some species have very small chromosomes, making an accurate count difficult. B chromosomes are common in Bignoniaceae.

Pollination is either entomophilous (via insects), ornithophilous (via birds), or chiropterophilous (via bats).

Taxonomy

The family Bignoniaceae was first validly published in the botanical literature (as Bignonieae) by Antoine Laurent de Jussieu in 1789 in his classic work, Genera Plantarum. The type genus for this family is Bignonia, which was validated by Linnaeus in Species Plantarum in 1753. The name originated with Joseph Pitton de Tournefort, who named it for his benefactor, Jean-Paul Bignon, in 1694, in his influential Eléments de botanique ou méthode pour connaître les plantes.

Important groundwork for future study of the family was laid down from 1789 to 1837, mostly by Jussieu, Kunth, Bojer and G.Don (George Don (1798–1856) not George Don the elder (1764–1814). Karl Moritz Schumann wrote a monograph on Bignoniaceae in 1894 for Engler and Prantl's Die Natürlichen Pflanzenfamilien. After Schumann's monograph, no taxonomic treatment of the entire family was published until 2004.

Classification

In the APG IV system of classification for flowering plants, Bignoniaceae is one of the 24 families in the order Lamiales. (Lamiales has 25 families if Rehmanniaceae are accepted). Within the order, Bignoniaceae is in a group of eight families consisting of Thomandersiaceae, Pedaliaceae, Martyniaceae, Schlegeliaceae, Bignoniaceae, Verbenaceae, Acanthaceae, and Lentibulariaceae. This group is described as a polytomy, meaning no two of its members are known to be more closely related to each other than to any of the others. In the 20th century, the only issues of circumscription were whether Paulowniaceae and Schlegeliaceae should be merged into Bignoniaceae, or accepted as separate families. Crescentiina is composed of two strongly supported clades, informally named the Tabebuia alliance and the Paleotropical clade. The tribe Crescentieae is embedded in the Tabebuia alliance and might be expanded to include Spirotecoma. Perianthomega has been transferred from Tecomeae sensu stricto to Bignonieae, where it is sister to the remainder of the tribe. Roseodendron and Handroanthus were resurrected from Tabebuia in 2007. Mayodendron and Pachyptera have been resurrected. Tabebuia heterophylla, and Tabebuia angustata are important sources of lumber for some of the Caribbean islands. Several species of Catalpa are also important timber trees.

Paratecoma was once the most important timber tree of the Rio de Janeiro area, but relentless exploitation has brought it to the verge of extinction. Its crushed leaves and stems are used to enervate bees while gathering honey.

Fridericia chica is the source of a red pigment used in the Amazon Basin for body paint and for dye in basketry.

References

Sources

Alwyn H. Gentry. 1992. "Bignoniaceae: Part II (Tecomeae)". Flora Neotropica Monograph 25(2):1-150. (See External links below).

External links

Bignoniaceae in L. Watson and M. J. Dallwitz (1992 onwards), The families of flowering plants.
Distribution Map Genus List Bignoniaceae Lamiales Trees APweb botanical databases About Science & Conservation Missouri Botanical Garden
Crescentieae and Tourrettieae At: Flora Neotropica 25(1) At: Flora Neotropica At: Organization for Flora Neotropica
tribe Tecomeae At: Flora Neotropica 25(2) At: Flora Neotropica At: Organization for Flora Neotropica
Bignoniaceae economic botany
List of genera in family Bignoniaceae At: Dicotyledons At: List Genera within a Family At: Vascular Plant Families and Genera At: About the Checklist At: World Checklist of Selected Plant Families At: Data Sources At: ePIC At: Scientific Databases At: Kew Gardens
Bignoniaceae At: Advanced Search At: Search Tool At: iplants
section B In: A checklist of suprageneric names (Alphabetical Listing by Genera) At: Home page of James L. Reveal & C. Rose Broome
Bignonia Plant Names IPNI
CRC World Dictionary of Plant Names: A-C At: Botany & Plant Science At: Life Science At: CRC Press
Bignoniaceae Genera Plantarum vol. 2 part 2 (Bentham & Hooker) View Record Titles beginning with "G" Titles Biodiversity Heritage Library
Spangler & Olmstead (1999)