1	"Petioles laterally compressed."	"Senna artemisioides subsp. x petiolaris"
1	"Petioles terete."	2
2	"Leaflets absolutely terete."	3
2	"Leaflets flat, 2 mm or broader, sometimes inrolled and then appearing terete."	4
3	"Leaves with 3–8 pairs of leaflets, 15–25 mm long, petiole <15 mm long."	"Senna artemisioides subsp. x artemisioides"
3	"Leaves with 1–4 pairs of leaflets, 20–40 mm long, petiole >15 mm long."	"Senna artemisioides subsp. filifolia"
4	"Leaflets conspicuously hairy."	5
4	"Leaflets glabrous or glabrescent."	9
5	"Leaflets obovate to ovate."	6
5	"Leaflets linear to elliptic."	7
6	"Leaflets woolly."	"Senna artemisioides subsp. helmsii"
6	"Leaflets silky."	"Senna artemisioides subsp. alicia"
7	"Leaflets linear and inrolled so that the upper surface is not visible."	"Senna artemisioides subsp. x artemisioides"
7	"Leaflets with upper surface exposed."	8
8	"Leaflets densely silky hairy to woolly hairy, never glaucous."	"Senna artemisioides subsp. x sturtii"
8	"Leaflets glabrous to sparsely hairy, glaucous."	"Senna artemisioides subsp. x coriacea"
9	"Leaflets obovate to ovate."	"Senna artemisioides subsp. alicia"
9	"Leaflets linear to elliptic to obovate."	10
10	"Leaflets >5 times as long as broad."	"Senna artemisioides subsp. zygophylla"
10	"Leaflets 1–4 times as long as broad."	11
11	"Leaflets 1–3 pairs, members of each leaflet pair carried more or less vertically with outer surfaces exposed."	"Senna artemisioides subsp. alicia"
11	"Leaflets 1–6 pairs, members of each leaflet pair carried almost horizontally"	"Senna artemisioides subsp. x coriacea"