1	"Bracteoles present"	2
1	"Bracteoles absent"	4
2	"Corolla campanulate or bilabiate; anthers 2-celled"	Centranthera
2	"Corolla salverform (with slender tube and spreading lobes); anthers 1-celled"	3
3	"Corolla tube straight; calyx faintly ribbed"	Buchnera
3	"Corolla tube decurved towards apex; calyx prominently ribbed"	Striga
4	"Sepals free for more than half their length"	5
4	"Sepals fused for more than half their length"	8
5	"Leaves alternate, at least in upper parts"	"Rhamphicarpa {Rhamphicarpa australiensis}"
5	"Leaves opposite or whorled"	6
6	"Fertile stamens 2, sometimes with 2 staminodes"	Lindernia
6	"Fertile stamens 4"	7
7	"Sepals broad, herbaceous, imbricate. Corolla over c. 2 cm long. Branches prominently 4-ribbed"	"Artanema {Artanema fimbriatum}"
7	"Sepals narrow, hardly overlapping. Corolla less than 1-5 cm long. Branches obscurely to distinctly 4-angled"	Lindernia
8	"Leaves opposite or whorled"	9
8	"Leaves alternate, at least in upper parts"	11
9	"Calyx equally 5-toothed, or unequally 3- to 4-toothed. Anther cells 2 or 1. Stigmas either 2 or 1, flap-like, or 2, terete. Leaves sometimes with scattered sessile glands. Roots without nodules"	Lindernia
9	"Calyx equally 4-toothed. Anther cells 2. Stigma capitate or obscurely obliquely 2-lobed. Leaves with patches of dense sessile glands below. Roots bearing parasitic nodules (haustoria). Capsule loculicidal"	10
10	"Seeds smooth or finely reticulate, c. 0.5 mm long. Capsule oblong"	Parentucellia
10	"Seeds longitudinally ribbed, scalariform between, c. 0.7 mm long. Capsule globular"	"Bartsia {Bartsia trixago}"
11	"Corolla strongly 2-lipped, the lips nearly equal"	"Triphysaria {Triphysaria pusilla}"
11	"Corolla 2-lipped, the lobes of the lower lip less than half the length of the upper"	"Castilleja {Castilleja exserta}"