Flores J., Jurado E., Jiménez-Bremont J. F., Breaking seed dormancy in specially protected Turbinicarpus lophophoroides and Turbinicarpus pseudopectinatus (Cactaceae), Plant Species Biology, 2008, 23(1):43-46, doi: 10.1111/j.1442-1984.2008.00206.x
A comparison of germination in two species from seed lots of different years and their responses to putrescine. The paper describes stored seeds and considers the hypothesis of a soil seed bank. In T. pseudopectinatus, the analysis indicates a significant effect of seed lot age, with no significant effect of putrescine.