Plants of South Eastern New South Wales
Grevillea diffusa
Common name
A grevillea
Family
Proteaceae
Where found
Dry forest and woodland, occasionally in swampy heath, usually on Hawkesbury sandstone. Coast and ranges north from the Illawarra.
subsp. constablei: Mainly Royal National Park and Heathcote National Park. Rarely elsewhere in the Sydney area.
subsp. diffusa: Coast and ranges north from east of Bowral.
subsp. filipendula: North from Mungamarra south of Broken Bay
Notes
Shrub to 2 m high. Leaves alternating up the stems, 1.5–13 cm long, 1–10 mm wide, margins entire and curved to rolled down or abruptly bent down, lower surface exposed, silky. Flowers with 4 'petals' joined together in pairs, 'petals' red or rarely green and brown, hairy outside, bearded inside. Gynoecium mostly 6–11 mm long; style red, sharply curved at about 1–1.5 mm from the tips. Flower clusters dense to loose. Flowers winter-spring.
In the absence of specific information, seeds of all species of Grevillea have been keyed as having one wing.
subsp. constablei: Open shrub 1–2 m high. Branchlets strongly angular in cross section, rarely turned to one side of the main stem, hairy to hairless. Leaves usually less than 7 cm long, margins more or less smoothly curved down. Perianth and style dark crimson to dark burgundy, style with wart-based hairs extending over top half. Flower clusters dense to loose, the main stalk angular, usually less than 1.5 cm long, hairy to hairless, usually zig-zagged.
subsp. diffusa: Branchlets more or less round or weakly angular in cross section, shortly tomentose. Leaves 1.5–5.5 cm long. Flower clusters dense, more or less stalkless or with short hairy stalks to 1 cm long, zig-zagged or not; style with wart-based hairs confined to about 1 mm towards the tips.
subsp. filipendula: Low spreading shrub less than 1 m high. Branchlets strongly angular in cross section, usually strongly turned to one side of the main stem, hairy to hairless. Leaves 6–15 cm long, margins abruptly bent down. Perianth and style scarlet to light burgundy, style with wart-based hairs extending over the top half. Flower clusters dense to loose, main stalk angular, usually 1.5–4 cm long, hairy to hairless, usually zig-zagged.
PlantNET description of species and key to subspecies: http://plantnet.rbgsyd.nsw.gov.au/cgi-bin/NSWfl.pl?page=nswfl&lvl=sp&name=Grevillea~diffusa (accessed 19 January, 2021)
This identification key and fact sheets are available as a free mobile application:
