| Rubiaceae | |
Galium serpenticum subsp. dayense
| Dempster & Ehrend. | Brittonia 17(4): 330, f. 4D [map] | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. malheurense
| Dempster & Ehrend. | Brittonia 17(4): 326, f. 4D [map] | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. okanoganense
| Dempster & Ehrend. | Brittonia 17(4): 329, f. 4D [map] | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. puberulum
| (Piper) Dempster & Ehrend. | Brittonia 17(4): 324 | 1965 |
| Rubiaceae | |
Galium serpenticum var. puberulum
| (Piper) Dempster | Brittonia 11(3): 121 | 1959 |
| Rubiaceae | |
Galium serpenticum subsp. scabridum
| (Ehrend.) Dempster & Ehrend. | Brittonia 17(4): 330 | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. scotticum
| Dempster & Ehrend. | Brittonia 17(4): 326, f. 4D [map] | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. serpenticum
| | | |
| Rubiaceae | |
Galium serpenticum subsp. warnerense
| Dempster & Ehrend. | Brittonia 17(4): 325, f. 4D, 6 [maps] | 1965 |
| Rubiaceae | |
Galium serpenticum subsp. wenatchicum
| Dempster & Ehrend. | Brittonia 17(4): 323, f. 4D, 5 [maps] | 1965 |