Grevillea rhyolitica 

Location & distribution maps

Common name:         Deua Grevillea

Conservation status: Rare

• It has been classified as a Rare or Threatened Australian Plant (ROTAP) due to its restricted range

Etymology:   

• The genus was named in honour of Charles Francis Greville, an 18th-century patron of botany and co-founder of the Royal Horticultural Society

• The specific epithet (rhyolitica) refers to the usual occurrence of this species on outcrops of rhyolite rock

Flowers:                  

• The flowers are arranged on the ends of branches or in leaf axils near the ends of branches, in down-curved, oval to more or less spherical clusters of mostly 5 to 18 on a rachis 10–20 mm long

• The clusters are on a thin, wiry peduncle 15–20 mm long, each flower on a pedicel 2–4 mm long

• The flowers are red and densely hairy except at the base, the pistil 16–20 mm long

• Flowering occurs from September to December

Fruit:                         

• A glabrous follicle 18–22 mm long with several longitudinal ridges

Leaves:         

• Elliptic, 40–110 mm long and 10–25 mm wide

• The upper surface is mostly glabrous and the lower surface sparsely hairy

Stem & branches: 

Roots:         

Habit:        

•  A more or less erect shrub that typically grows to a height of 0.5–2 m 

Habitat:   

• Moist gullies and in steep rocky ridges on rhyolite in montane areas

Distribution:                  

• West and south-west of Moruya

• Subspecies semivestita grows forest in broken escarpment country north-west of Moruya in south-eastern NSW

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Additional notes:    

• Taxonomy

  • Grevillea rhyolitica was first formally described in 1997 by Robert Owen Makinson in the journal Telopea from specimens collected in 1990 by David Albrecht

  • In 2000, Makinson described two subspecies of G. rhyolitica in the Flora of Australia, and the names are accepted by the Australian Plant Census:

    • Grevillea rhyolitica Makinson subsp. rhyolitica has leaves with raised hairs on the lower surface

    • Grevillea rhyolitica subsp. semivestita Makinson has leaves with scattered hairs pressed against the lower surface

Sources of information:

• https://en.wikipedia.org/wiki/Grevillea_rhyolitica (2024)

• https://www.anbg.gov.au/gnp/interns-2003/grevillea-rhyolitica.html#:~:text=It%20has%20been%20classified%20as,due%20to%20its%20restricted%20range (2024)