These species of herbs are well distributed over all Rio Grande do Sul State, and are used to prepare medicine for the human population. The influence of constant temperatures (10ºC; 15ºC; 20ºC; 25ºC; 30ºC and 35ºC) on the germination of seeds during a photoperiod of 8 hours, was analyzed. Experiments were also performed in darkness, and at alternating temperatures (10-20ºC; 15-25ºC; 20-30ºC; 25-35ºC). Seeds that did not germinate were submitted to the tetrazolium test. Over 80% of the seeds of B. antiacantha germinated at constant temperatures of 25º, 30º or 35ºC, both in light and darkness. Below 25ºC, the seeds presented relative dormancy. Storage during one year under laboratory conditions (25ºC), or at a low temperature (5ºC) allowed for 90% of seed viability. Over 80% of the seeds of C. cartliagensis germinated at alternating temperatures, but no germination was observed at constant temperatures, although the seeds remained viable. T. patens presented over 50% of deteriorated seeds and final germination was similar at constant and alternating temperatures. The three species can be propagated through seeds, if the appropriate temperature requirements are observed for each of them.
Bromelia; Cuphea; Talinum; light; temperature; germination