The flowers are pink to red and yellow or green with a reddish style, the pistil 9.5–14 mm (0.37–0.55 in) long.

Flowering occurs from October to December and the fruit is a hairy follicle 12–15 mm (0.47–0.59 in) long.

[2][3][4] Grevillea polybractea was first formally described in 1927 by Herbert Bennett Williamson in The Victorian Naturalist.

[7] Crimson grevillea grows in forest with a scrubby understorey, and occurs south of Dubbo and west of Khancoban in New South Wales, and between Corryong and Mount Granya in far north-eastern Victoria.

This grevillea is listed as "endangered" under the Victorian Government Flora and Fauna Guarantee Act 1988[4] and as "rare in Victoria" on the Department of Sustainability and Environment's Advisory List of Rare or Threatened Plants in Victoria.