Spyridium bifidum

Spyridium bifidum is an erect shrub that typically grows to a height of up to 2 m (6 ft 7 in), its young stems densely covered with simple and star-shaped hairs. The leaves are wedge-shaped to linear, 3.2–13 mm (0.13–0.51 in) long and 1–5 mm (0.039–0.197 in) wide on a petiole 0.7–1.5 mm (0.028–0.059 in) long. The edges of the leaves are rolled under, the tip is sometimes forked with two lobes, both surfaces are covered with soft, star-shaped hairs, and there are triangular to narrowly egg-shaped stipules at the base. The more or less spherical heads of "flowers" are 8–12 mm (0.31–0.47 in) wide, the individual flowers more or less sessile and silky-hairy. Each head is surrounded by 4 or 5 velvety, white leaves, each more or less divided into two. The fruit is a light brown capsule 2.2–2.5 mm (0.087–0.098 in) long.[2][3]

This species was first formally described in 1855 by Ferdinand von Mueller who gave it the name Trymalium bifidum in his Definitions of rare or hitherto undescribed Australian plants.[4][5] In 1863, George Bentham changed the name to Spyridium bifidum in Flora Australiensis.[6] The specific epithet (bifidum) refers to the forked leaves of this species.[3]

In 2012, Jürgen Kellermann and William Robert Barker described two subspecies of Spyridium bifidum in the journal Muelleria and the names are accepted by the Australian Plant Census:

• Spyridium bifidum (F.Muell.) F.Muell. ex Benth. subsp. bifidum[7] has wedge-shaped to heart-shaped leaves with a Y-shaped tip;[2]
• Spyridium bifidum subsp. wanillae Kellermann & W.R.Barker[8] has narrowly lance-shaped to narrowly oblong or linear leaves that are rarely forked at the tip.[2]

Spyridium bifidum grows in mallee shrubland on the Marble Range and on the hills to the east of Edillilie, the two subspecies separated by only 5 or 6 km (3.1 or 3.7 mi). Subspecies bifidum is restricted to the Marble Range, and flowers from June to September, subspecies wanillae is mostly found around Wanilla on the Eyre Peninsula, and flowers in July.[2]