Grevillea ‘Poorinda Diadem’ is an erect shrub that reaches a height of two metres with a similar width.
The leaves are 30 millimetres long by 8 millimetres wide, dark green above, paler below, shiny with a pointed tip.
A grevillea inflorescence is technically a cluster of paired flowers, termed a conflorescence with the overall structure forming a raceme-like appearance. Grevillea species exhibit 3 main inflorescence structures:
1. A cylindrical to ovoid raceme (with flowers emerging around a 360° radius)
2. A single-sided raceme (with flowers produced on only one side, resembling a tooth-brush)
3. A condensed or clustered raceme (usually as long as it is wide, with species referred to as the spider-flowers)
Grevillea mostly produce the inflorescences at the terminals, beyond the foliage, which differs to the closely related Hakea.
This cultivar has large spider-inflorescences (though they are carried in the leaf axils but usually beyond the foliage). They are apricot to buff-coloured with long yellow styles, conspicuous and profuse. Individual flowers are composed of 1 carpel (female part) where the style and stigma protrude out; 4 stamens hidden away in the perianth; and the perianth (petals and sepals collectively) which connects to a pedicel. Proteaceae flowers do not have any discernible petals or sepals (having only one whorl) and so these are referred to as “tepals” of which there are 4. In this cultivar, the carpels are to 40 mm long, yellow to apricot with darker tips. Flowering commences in late winter and extends for a number of months.
The flowers are displayed well against the dark foliage. Honeyeaters are attracted to the blooms.
The Poorinda hybrids were developed by the late Leo Hodge on his Victorian property. In general, including ‘Poorinda Diadem’, all Leo’s hybrids are hardy and free flowering. Unfortunately most appear to have gone out of “horticultural fashion”.
Plant in a sunny site on well-drained soils for best results. Very frost tolerant and hard once established. Responds well to pruning
Must be propagated from cuttings to retain ‘true-to-type’ form.
Grevillea is a diverse genus of about 360 species of evergreen flowering plants native to rainforest and more open habitats in Australia, New Guinea, New Caledonia, Sulawesi and other Indonesian islands east of the Wallace Line. NSW currently has about 85 species although with a lot of subspecies and some informal taxa recognised.
Grevillea flowers were a traditional favourite among First Nations Peoples for their sweet nectar. This could be shaken onto the hand to enjoy, or into a coolamon with a little water to make a sweet drink. They might be referred to as the original “bush lollies”.
Grevillea ‘Poorinda Diadem’ is said to be a seedling of G. Poorinda ‘Leanne’ and was registered in the 1970’s.
Grevillea – was named in honour of Charles Francis Greville (1749-1809), an 18th-century patron of botany and co-founder of the Royal Horticultural Society. He was also a British antiquarian, collector and politician who sat in the House of Commons from 1774 to 1790.
‘Poorinda Diadem’ – named for the property ‘Poorinda’ in Victoria from where many grevillea cultivars have arisen. ‘Diadem’ likely refers to the showy inflorescences.
Australian National Botanic Gardens – Australian Cultivar Resgistration Authority – Grevillea ‘Poorinda Diadem’ profile page https://acra.biodiversity.services/info/rdetail/654
Eureka Nursery – Grevillea ‘Poorinda Diadem’ sales page https://plantsale.com.au/rfq/?plant_id=GrPoDi