| Sphaerium lacryma (L.) Kuntze, 1891 |
| Sphaerocarpa Hitchc. & Chase, 1910 |
| Sphenopholis Scribn., 1906 |
| Sphenopholis annua (Suksd.) A. Heller, 1910 |
| Sphenopholis hallii (Scribn.) Scribn., 1906 |
| Sphenopholis interrupta (Buckley) Scribn., 1906 |
| Sphenopholis interrupta subsp. californica (Vasey) Scribn., 1906 |
| Sphenopholis interrupta subsp. interrupta (Buckley) Scribn., 1906 |
| Sphenopholis obtusata (Michx.) Scribn., 1906 |
| Sphenopholis obtusata f. obtusata (Michx.) Scribn., 1906 |
| Sphenopholis obtusata f. purpurascens (Vasey ex Rydb. & Shear) Waterf., 1948 |
| Sphenopholis obtusata subsp. lobata (Trin.) Scribn., 1906 |
| Sphenopholis obtusata subsp. pubescens (Scribn. & Merr.) Scribn., 1906 |
| Sphenopholis obtusata var. lobata (Torr.) Scribn. ex B.L. Rob., 1908 |
| Sphenopholis obtusata var. obtusata (Michx.) Scribn., 1906 |
| Sphenopholis obtusata var. pubescens (Scribn. & Merr.) Scribn. ex B.L. Rob., 1908 |
| Sphenopholis pubescens (Scribn. & Merr.) A. Heller, 1910 |
| Sphenopholis robusta (Vasey ex L.H. Dewey) A. Heller, 1910 |
| Spirochloe Lunell, 1915 |
| Spirochloe paniculata (Nutt.) Lunell, 1915 |