1	"Seeds 2; leaf +- round to +- elliptic in ×-section"	"Lycium californicum"
1	"Seeds several to many; leaf elliptic to +- flat in ×-section"	2
2	"Calyx lobes 1/2 to > tube or generally > 2 mm"	3
2	"Calyx lobes < 2/3 tube or generally < 2 mm"	7
3	"Fruit firm, green-purple or yellow to orange"	4
3	"Fruit soft, red"	5
4	"Leaves glandular-puberulent, not glaucous; fruit yellow to orange, with 2 cross-grooves above middle"	"Lycium cooperi"
4	"Leaves glabrous, glaucous; fruit green-purple, not cross-grooved"	"Lycium pallidum var. oligospermum"
5	"Stamens glabrous, attached near tube top"	"Lycium verrucosum"
5	"Stamens hairy at base, attached near tube middle."	6
6	"Leaves generally glabrous; corolla generally 4-lobed"	"Lycium brevipes var. hassei"
6	"Leaves glandular-puberulent; corolla 5-lobed"	"Lycium parishii"
7	"Branches curved to arched, thorns 0--1(2) cm"	"Lycium barbarum"
7	"Branches not curved to arched, thorns 1--5 cm"	8
8	"Corolla lobes 1/3 to = tube"	"Lycium brevipes var. brevipes"
8	"Corolla lobes < 1/3 tube"	9
9	"Plant glandular-hairy"	"Lycium fremontii"
9	"Plant +- glabrous"	10
10	"Corolla lobe margin glabrous to finely straight-ciliate; leaf +- linear-oblanceolate"	"Lycium andersonii"
10	"Corolla lobe margin woolly-ciliate; leaf narrowly oblanceolate to obovate"	"Lycium torreyi"