Brachychiton

taxobox
name = "Brachychiton"


image_caption = "Brachychiton acerifolius"
regnum = Plantae
unranked_divisio = Angiosperms
unranked_classis = Eudicots
unranked_ordo = Rosids
ordo = Malvales
familia = Malvaceae
genus = "Brachychiton"
genus_authority = Schott & Endl.
subdivision_ranks = Species
subdivision = See text.|

"Brachychiton" (Kurrajong, Bottletree) is a genus of 31 species of trees and large shrubs, native to Australia (the centre of diversity, with 30 species), and New Guinea (one species). Fossils from New South Wales and New Zealand are estimated to be 50 million years old, corresponding to the Tertiary.

They grow to 4 – 30m tall, and some are dry-season deciduous. Several species (though not all) are pachycaul plants with a very stout stem for their overall size, used to store water during periods of drought. The leaves show intraspecific variation and generally range from entire to deeply palmately lobed with long slender leaflet-like lobes joined only right at the base. Their sizes range from 4 – 20cm long and wide.

All species are monoecious with separate male and female flowers on the same plant. The flowers have a bell-shaped perianth consisting of a single series of fused lobes which is regarded as a calyx despite being brightly coloured in most species. The female flowers have five separate carpels that can each form a woody fruit containing several seeds. The flower colour is often variable within species. Eastern forest species drop their foliage before flowering but those of the dryer regions carry the flowers while in leaf.

The name "Brachychiton" is derived from the Greek "brachys", short, and "chiton", tunic, in referring to its loose seed coats. The generic name is often misconstrued as being of neuter gender, with the specific names then incorrectly amended. Thus "B. rupestre" and "B. populneum" are sometimes seen in horticultural books and magazines.

"Kurrajong" is an Aboriginal word for "fibre-yielding-plant" Fact|date=July 2007 and refers to the use of bark from many of these trees for weaving nets, ropes and baskets. A few Kurrajong species are popular garden trees and have been introduced to hot dry regions including the Mediterranean, South Africa and the western United States. These species are also hybridised for horticultural purposes, "B. populneo-acerifolius" being one example. Kurrajongs are however irregular flowerers.

elected species

References

*Guymer, G.P. (1988) A taxonomic revision of Brachychiton (Sterculiaceae). "Australian Systematic Botany" 1: 199-323.
*Macoboy, S. (1991) What tree is that?, ISBN 1 86302 1310

External references

* [http://www.bigscrubrainforest.org.au/bigscrub3.html Note on fossil age, Big Scrub Rainforest]
* [http://www.malvaceae.info/Fossil/Leaf.html Notes on Fossil Leaves, Stewart R. Hinsley, 2005]