Germination of four species of the genus Mimosa (leguminosae) in a semi-arid zone of Central Mexico

Mimosa depauperata, M. lacerata, M. similis, and M. texana var. texana are dominant leguminous shrubs in the semi-arid region of Queretaro, in central Mexico. These species grow and reproduce under conditions of disturbance; they are occasionally browsed by goats and used for firewood. The effect of temperature on germination, the longevity of the seeds in the field, and the germination potential of seeds parasitized by insects of the family Bruchidae were tested. It was found that the seeds require scarification to germination. The optimum temperature for seed germination of M. similis, M. lacerata, and M. depauperata was between 20°C and 35°C and for M. texana var. texana between 30°C and 35°C. The species germinated just as well beneath the canopy as in open areas in the field. The seeds of each species are parasitized by bruchids of the genus Acanthocelides spp., and seed infestation necessarily had a detrimental effect. The seeds in the seed bank lose their longevity at a rate of 20–73% per year. As with other legumes, Mimosa seeds have a tough seed coat, which influences germination, longevity, and susceptibility to predation by bruchids. The results form this study contribute to an understanding of the phases of germination and the longevity of the seeds of Mimosa in the seed bank in arid and semi-arid communities.