Grevillea.
Family Proteaceae > Subfamily Grevilleoideae > Tribe Embothrieae > Subtribe Hakeinae.
There are around 360 species most of which are native to Australia.
They are commonly known just as Grevillea.
The evergreen plants are mostly shrubs from 50 cm high to a few trees up to 35 m.
There are flattened hairs on various parts.
Leaves are alternate and can be simple (needle-like or broad), toothed or 2 or 3 times divided.
They can be dark to yellow green, grey or blue-green and flat or with the edges rolled under.
Inflorescences are commonly terminal but can also be axillary.
They consist of 1 up to 100 or more small flowers typically in pairs along a central axis.
They are divided into ‘spider’, ‘brush’ and ‘toothbrush’ types.
In the spider types the flowers form a rounded inflorescence said to resemble a spider’s legs.
The toothbrush types have inflorescences with the flowers on one side.
The brush types have larger, cylindrical inflorescences.
Each bisexual flower has 4 coloured tepals initially fused into a long tube with a swollen tip.
Inside the tepals the hypogynous glands are mostly fused into a partial ring.
The copious amounts of nectar attracts honeyeaters and other pollinators.
The anthers, without filaments, are inside the swollen tepal tips.
The superior ovary is mostly on a stalk or gynophore.
There is a long style with a terminal stigma on the disc or cone-like pollen presenter.
When the pollen is mature it is deposited on the pollen presenter that lies among the anthers.
After this the tepal tube splits along one side and the style bends out but the tip remains between the anthers.
The tip then becomes free of the tepals and the style usually straightens.
The stigma then becomes receptive to pollen from another flower or plant.
The tepals remain attached to each other after the tube splits but then may separate.
Grevilleas flower all year in colours such as yellow, orange, red, pink, white, cream, mauve or greyish.
Some have 2 colours.
The fruit are follicles, usually curved that contain 1 or 2 flat seeds.
The seeds commonly have a membranous, varioiusly shaped wing.
Grevilleas are popular garden plants with thousands of types and colours to choose from.
There are species plants, different forms of some species, a large range of natural hybrids and some cultivars.
They are sold under a wide range of commercial names.
J.F.
