| | 1. Shrub; leaves 3–9 mm, not reduced upward, oblong to ovate, puberulent |
| S. damascena |
| | 1' Annual; leaves 5–55 mm, generally reduced upward, thread-like to lanceolate, base generally wide in fruit |
| |
| | 2. Plants fleshy in fruit; calyx 3.5–5 mm, outer sepals winged in fruit, inner (facing stem) tubercled in fruit |
| S. soda |
| | 2' Plants not fleshy in fruit; calyx 2.5–3.5 mm, all sepals winged in fruit |
| |
| | 3. Sepal wings 2.5–4.5 mm in fruit; leaves yellow-green; branchlets often minutely papillate |
| S. paulsenii |
| | 3' Sepal wings 0.5–2.5 mm in fruit; leaves ± green; branchlets often short-stiff-hairy |
| S. tragus
|