1	"Leaves terete or nearly so."	"Darwinia fascicularis"
1	"Leaves laterally compressed, keeled."	2
2	"Bracteoles extending beyond perianth; style recurved, with hairs in a lateral tuft."	"Darwinia taxifolia"
2	"Bracteoles shorter than perianth; style straight or curved, hairs usually in a ring."	3
3	"Sepals more than three-quarters the length of petals; hypanthium papillate between ribs."	4
3	"Sepals less than three-quarters the length of petals; hypanthium smooth between ribs (rarely slightly papillate in D. leptantha)."	5
4	"Hypanthium 7–12 mm long; style 12–20 mm long."	"Darwinia grandiflora"
4	"Hypanthium 3–5 mm long; style 4–9 mm long."	"Darwinia diminuta"
5	"Flowers, including style, 4–9 mm long; bracteoles yellow-green or yellow-brown."	6
5	"Flowers, including style, 9–25 mm long; bracteoles dark brown or red-purple."	8
6	"Hypanthium more or less 0.5 mm diam., bracteoles 2–3.5 mm long, caducous."	"Darwinia leptantha"
6	"Hypanthium 1–2 mm diam., bracteoles 3.5–6 mm long, persisting until after anthesis."	7
7	"Hypanthium glabrous between the broad or rounded longitudinal ribs."	"Darwinia camptostylis"
7	"Hypanthium papillose between the distinct narrow ribs."	"Darwinia briggsiae"
8	"Hypanthium ± 1.5 mm diam., with distinct glaucous ridges."	9
8	"Hypanthium 1.5–2.5 mm diam., ribs obscure or broad and rounded."	10
9	"Leaves glaucous, 8–17 mm long; bracteoles red-brown, caducous."	"Darwinia glaucophylla"
9	"Leaves green, 6–10 mm long; bracteoles purple-red, persisting till after anthesis."	"Darwinia biflora"
10	"Peduncles 4–7 mm long; style 6–10 mm long."	"Darwinia peduncularis"
10	"Peduncles 1–2 mm long; style 14–20 mm long"	"Darwinia procera"