It is a dense, mat forming, prostrate shrub with clusters of tubular red flowers and is endemic to New South Wales.

Darwinia grandiflora is a prostrate, mat forming, dense shrub up to 50 cm (20 in) high and stems up to 2.5 m (8 ft 2 in) long with smaller branches growing upright.

Flowering occurs usually from July to October and the fruit is a small 2.4 mm (0.094 in) in diameter single seed.

[4] In 1917 Richard Thomas Baker & Henry George Smith raised the variety to species status to Darwinia grandiflora and the description was published in Journal and Proceedings of the Royal Society of New South Wales.

[3] Darwinia grandiflora grows in wet heath, damp sandy soil and rocky outcrops south of Sydney on the Woronora Plateau and in the Illawarra region.