The Grevilleoideae are a subfamily of the plant family Proteaceae. Mainly restricted to the Southern Hemisphere, it contains around 46 genus and about 950 species. Genera include Banksia, Grevillea, and Macadamia.
Description
The Grevilleoideae grow as
,
, or
. They are highly variable, making a simple, diagnostic identification key for the subfamily essentially impossible to provide. One common and fairly diagnostic characteristic is the occurrence of flowers in pairs that share a common
bract. However, a few Grevilleoideae taxa do not have this property, having solitary flowers or
of unpaired flowers. In most taxa, the flowers occur in densely packed heads or spikes, and the
fruit is a follicle.
Distribution and habitat
Grevilleoideae are mainly a Southern Hemisphere family. The main centre of diversity is
Australia, with around 700 of 950 species occurring there, and
South America also contains taxa. However, the Grevilleoideae are barely present in
Africa, where almost all of Proteaceae taxa belong to the subfamily
Proteoideae.
The lone exception and only grevilleoid in Africa is the
Brabejum tree of
Cape Town.
Taxonomy
The framework for classification of the Proteaceae was laid by L.A.S. Johnson and Barbara Briggs in their 1975 monograph "".
Their classification has been refined somewhat over the ensuing three decades, most notably by Peter H. Weston and Nigel Barker in 2006. The Grevilleoideae are now considered one of five subfamilies of the Proteaceae. The placement and circumscription of the Grevilleoideae in four tribes, according to Weston and Barker can be summarised as:
- ::: Sphalmium — Carnarvonia
roupaleae">
Roupaleae
Authority: Meisn.
- ::incertae sedis
- ::: Megahertzia — Knightia — Eucarpha — Triunia
- ::Subtribe Roupalinae L.A.S.Johnson & B.G.Briggs
- ::: Roupala — Neorites — Orites
- ::Subtribe Lambertiinae (Venk.Rao) L.A.S.Johnson & B.G.Briggs
- ::: Lambertia — Xylomelum
- ::Subtribe Heliciinae L.A.S.Johnson & B.G.Briggs
- ::: Helicia — Hollandaea
- ::Subtribe Floydiinae L.A.S.Johnson & B.G.Briggs
- ::: Darlingia — Floydia
banksieae">
Banksieae
Authority: Rchb.
- ::fossil form genera
- ::: Banksieaeidites — Banksieaeformis — Banksieaephyllum
- ::Subtribe Musgraveinae L.A.S.Johnson & B.G.Briggs
- ::: Musgravea — Austromuellera
- ::Subtribe Banksiinae L.A.S.Johnson & B.G.Briggs
- ::: Banksia
embothrieae">
Embothrieae
Authority: Rchb.
- ::Subtribe Lomatiinae L.A.S.Johnson & B.G.Briggs
- ::: Lomatia
- ::Subtribe Embothriinae Endl.
- ::: Embothrium — Oreocallis — Alloxylon — Telopea
- ::Subtribe Stenocarpinae L.A.S.Johnson & B.G.Briggs
- ::: Stenocarpus — Strangea
- ::Subtribe Hakeinae Endl.
- ::: Opisthiolepis — Buckinghamia — Hakea — Grevillea — Finschia
macadamieae">
Macadamieae
Authority: Venk.Rao
- ::Subtribe Macadamiinae L.A.S.Johnson & B.G.Briggs
- ::: Macadamia — Panopsis — Brabejum
- ::Subtribe Malagasiinae P.H.Weston & N.P.Barker
- ::: Malagasia — Catalepidia
- ::Subtribe Virotiinae P.H.Weston & N.P.Barker
- ::: Virotia — Athertonia — Heliciopsis
- ::Subtribe Gevuininae L.A.S.Johnson & B.G.Briggs
- ::: Cardwellia — Euplassa — Gevuina — Bleasdalea — Hicksbeachia — Kermadecia
Uses
The nursery industry cultivates many Grevilleoideae species as barrier plants and for their prominent and distinctive flowers and foliage. Some species are of importance to the
floristry, especially some
Banksia and
Dryandra species. Two species of the genus
Macadamia and the Chilean species
Gevuina avellana (Chilean hazel) are grown commercially for edible nuts. Chilean hazel has an acceptable frost tolerance.
