Elliptical leaves, about 4-14 per plant, are scattered along the elongate, glabrous stem.

Inflorescences are 5–20 cm long and produce pink or mauve flowers that bloom in June in the southern hemisphere.

The populations of S. longissimum inhabit an area of less than 30 km2 and the actual coverage is much less than that,[2] which is why A.R.

Bean recommended a conservation status of vulnerable when he described this species in 2000.

[1] Its habitat is recorded as being sandy soils in Melaleuca viridiflora woodlands.