Thanks peren.

As far as I can see, White Knight has more compact flower clumps than this one.

Also wondering about Grevillea gracilis alba

" Also wondering about Grevillea gracilis alba "

That seems very plausible although there seems to be a lot of taxonomic confusion regarding this name. Some sites just refer to it as Grevillea alba.

I've done some checking on-line and according to:

RHS, the name is unresolved

Atlas of Living Australia (www.ala.org.au), neither G. gracilis or G.alba are listed. The only species with var alba is a synonym for G. linearifolia, which this isn't.

Kew Garden's Plants of the World (powo.science.kew.org), likewise lists neither.

When I lived in Aus, I had several Grevillea in my garden and had noticed that new hydrids/cultivars were being offered for sale everytime I visited a garden centre.

To quite from "Pollen characteristics of grevillea species determined by in vitro germination". by Rebecca Parsons, Edith Cowan University:-

"Despite the low levels of hybridisation evident in the wild, under horticultural conditions, grevilleas hybridise relatively easily. It is possible that under natural conditions, species that have the ability to hybridise under horticultural conditions are spatially or temporally separated in the wild, therefore unable to ever cross pollinate." https://ro.ecu.edu.au/theses_hons/1127

I guess that this is just another of the cultivars/hybrids that are churned out, ten-to-the-dozen, in Australia (& globally?).

C'est la vie!

I wonder what the foliage feels like of both Grevillea White Knight and G. gracilis alba. Apparently G gracilis alba has needle-like foliage, but what about G. White Knight? Anybody know? If I see one somewhere I will test it out.

Is rosmarinifolia lutea on the list somewhere?

G. rosmarinifolia lutea isn't listed on ALA, Kew's POWO or RHS