# Grevilleoideae

The Grevilleoideae are a subfamily of the plant family Proteaceae. Mainly restricted to the Southern Hemisphere, it contains around 46 genera and about 950 species. Genera include Banksia, Grevillea, and Macadamia.

## Description

The Grevilleoideae grow as trees, shrubs, or subshrubs. 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 inflorescences 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 "On the Proteaceae: the evolution and classification of a southern family". 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:
* Tribe incertae sedis
             Sphalmium — Carnarvonia

### 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

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

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

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 cut-flower industry, 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.