References

For Phacelia

Constance, L. 1949. A revision of Phacelia subgenus Cosmanthus (Hydrophyllaceae). Contr. Gray Herb. 168: 1-48.

Gillett, G.W. 1964. Genetic barriers in the Cosmanthus Phacelias (Hydrophyllaceae). Rhodora 66: 359-368.

Gillett, G.W. 1968. Systematic relationships in the Cosmanthus Phacelias (Hydrophyllaceae). Brittonia 20: 368-374.

Hofmann et al. 2016. In Kadereit, J.W., and V. Bittrich. 2016. The families and genera of flowering plants. XIV. Flowering plants – Eudicots – Aquifoliales, Boraginales, Bruniales, Dipsacales, Escalloniales, Garryales, Paracryphiales, Solanales (except Convolvulaceae), Icacinaceae, Metteniusaceae, Vahliaceae. Springer, Berlin. 412 pp.

Levy, F. 1991a. Morphological differentiation in Phacelia dubia and P. maculata. Rhodora 93: 11-25.

Levy, F. 2021. Evaluation of the taxonomy of Phacelia purshii (Hydrophyllaceae). J. Torrey Bot. Soc. 148(1): 1-16.

Levy, F., and K. A. Malone. 2001. Phacelia dubia in South Carolina: the interface of morphology, genetics and taxonomy. Castanea 66:134-144.

Levy, F., Z.H. Hou, and S. Taylor-Bennetts. 2021. A new variety of Phacelia dubia (Hydrophyllaceae) and a summary of variation and biogeography of the P. dubia complex. J. Torrey Bot. Soc. 148: 266-284.

Murdy, W.H. 1966. The systematics of Phacelia maculata and P. dubia var. georgiana, both endemic to granite outcrop communities. Amer. J. Bot. 53: 1028-1036.

Sewell, M., and M.A. Vincent. 2006. Biosystematics of the Phacelia ranunculacea Complex (Hydrophyllaceae). Castanea 71:192-209.