The Restionaceae, also called restiads and restios, are a family of native to the Southern Hemisphere; they vary from a few centimeters to 3 meters in height. Following the APG IV (2016):[Bremer, K. (2002). "Gondwanan Evolution of the Grass Alliance of Families (Poales)." Evolution, 56(7): 1374-1387. [1] ]
Description
The family consists of tufted or rhizomatous, herbaceous plants belonging to a group of
that includes several similar families, such as the
Cyperaceae,
Juncaceae, and
Poaceae. They have green, photosynthetic stems and leaves that have been reduced to sheaths. Their flowers are extremely small and in spikelets, which in turn make up the inflorescences. Male and female flowers are on separate plants and, like grasses, are
anemophilous.
Distribution
Plants in the family are distributed on all the southern continents -
South America (two spp.,
Apodasmia chilensis and
Gaimardia australis),
Africa south of the Equator and including
Madagascar (about 330 spp.) and
Australia (about 150 spp.) - in
New Zealand (four spp.) and widely distributed in
Southeast Asia (one sp.). They are often dominant elements of the flora in the
Mediterranean climates of
South Africa and Western Australia. They are the defining family in the
Western Cape fynbos plant community.
The South American species is very similar to one of the New Zealand species, leading to the conjecture that it might have crossed the
Pacific Ocean in the last 30 million years. The distribution of restios in Africa is irregular, with the same single species occurring in Madagascar, the Democratic Republic of the Congo,
Tanzania, and
Malawi, while a different species is found in the Chimanimani Mountains of eastern
Zimbabwe. Four species are found in the
Drakensberg, one of which spills over into
Mpumalanga and
Limpopo provinces. The vast majority of species, though, are to be found in the Cape Floristic Region and particularly plentiful on hard sandstone formations. The center of diversity lies in the
Kogelberg, where more than a third of all Restionaceae may be found.
[ Restios of the Fynbos - Els Dorrat Haaksma, H. Peter Linder (Botanical Society of South Africa, 2000)] Restionaceae are grown in
Kirstenbosch,
Cape Town's National Botanical Gardens.
A number of the largest African species have become popular as garden ornamentals in many parts of the world, some being useful as accent plants similar to small species of bamboo, but with pendant stems of greater delicacy. Also, many smaller species offer a great variety of decorative features and deserve horticultural attention.
Taxonomy
The family Restionaceae has been recognized by most taxonomists. The APG II system of 2003 (unchanged from the
APG system, 1998), recognizes this family and assigns it to the order
Poales, in the clade
commelinids of the
monocots. The
Cronquist system of 1981 also recognized this family and placed it in the order
Restionales, in the subclass
Commelinidae in class
Liliopsida in division
Magnoliophyta.
Genera
,
Kew's Plants of the World Online lists the following 48 genera in the family Restionaceae:
External links
