| | 1. Corolla lobes hairy inside, ± = throat (subg. Symphoricarpos) |
| |
| | 2. Plant 6–18 dm, erect; corolla swollen on 1 side, glandular within swelling; inflorescence generally 8–16-flowered |
| S. albus var. laevigatus |
| | 2' Plant 1.5–6 dm, sprawling; corolla scarcely or not swollen, nectary glands 5, below all corolla lobes; inflorescence generally 2–8-flowered |
| S. mollis |
| | 1' Corolla lobes glabrous inside, << throat or tube (subg. Anisanthus) |
| |
| | 3. Corolla ± salverform, 8–15 mm, tube slender, glabrous inside, 3–4 × length of spreading lobes; nectary 1; leaf ± similar above and below, blade generally 4–12 mm |
| S. longiflorus |
| | 3' Corolla bell-shaped, 6–10 mm, tube wide, ± hairy inside, 2–3 × length of erect lobes; nectaries 5; leaf more obviously veined below, blade generally 8–20 mm |
| S. rotundifolius |
| | 4. Plant trailing; upper 2/3 corolla throat sparsely hairy inside; s High Sierra Nevada, Southwestern California, East of Sierra Nevada, Desert Mountains |
| var. parishii |
| | 4' Plant erect, spreading; upper 1/3 of corolla tube glabrous inside, middle 1/3 hairy; Cascade Range, Sierra Nevada, Great Basin Floristic Province |
| var. rotundifolius
|