Isopogon sphaerocephalus subsp. sphaerocephalus (Drumstick Isopogon)

Isopogon sphaerocaphalus is a shrub that typically grows to a height of 0.3–2 m (1 ft 0 in – 6 ft 7 in) and has hairy brownish young branchlets and hairy young leaves. The leaves are linear to egg-shaped with the narrower end towards the base, 50–160 mm (2.0–6.3 in) long and 4–18 mm (0.16–0.71 in) wide with a small point on the end. The flowers are arranged on the ends of branchlets in sessile, spherical heads 25–30 mm (0.98–1.18 in) in diameter with hairy, egg-shaped involucral bracts at the base. The flowers are densely hairy, white to pale or creamy yellow and up to 15 mm (0.59 in) long. Flowering occurs from July to January and the fruit is a hairy nut, fused with others in a conical to oblong head 20–30 mm (0.79–1.18 in) in diameter.

Isopogon sphaerocephalus was first formally described by botanist John Lindley in A sketch of the vegetation of the Swan River Colony in 1839.

In 2019, Barbara Lynette Rye described two subspecies of I. sphaerocephalus in the journal Nuytsia but the names have not been assessed by the Australian Plant Census as at November 2020:

Isopogon sphaerocephalus Lindl. subsp. sphaerocephalus, commonly known as "drumstick isopogon";
Isopogon sphaerocephalus subsp. lesueurensis Rye, commonly known as "Lesueur isopogon" has a longer pollen presenter, hairier branchlets and leaves and more crowded, broader leaves than the autonym.
The specific epithet (sphaerocephalus) means "spherical-headed", and lesueurensis refers to Mount Lesueur, where this subspecies occurs.