-(Germination behaviour of epiphyte and rupicolous Bromeliaceae species from Ibitipoca State Park, Minas Gerais, Brazil). The germination behaviour of four Bromeliaceae species [Alcantarea imperialis (Carrière) Harms, Pitcairnia fl ammea Lindl., Vriesea heterostachys (Baker) L. B. Sm. and Vriesea pendulifl ora L. B. Sm.] from Ibitipoca State Park with contrasting habitat preferences, and representing two different plant growth forms were investigated. The aims of this study were: a) to characterize the seeds, providing information about germination type to describe the post-seminal development morphology; b) to evaluate percentage and rate of germination response to the effect of constant (from 10 °C to 40 °C) and fl uctuating (20 °C-30 °C) temperatures; c) the ratio of red:far-red light (R:FR) and d) to different water potentials. The results showed that all species have very light seeds, ranging from 0.2 to 1.7 mg; the germination is epigeal with cryptocotylar seedlings. All species presented high germination under temperatures between 20 °C and 30 °C. Under darkness germination was successful only for Vriesea species, but seeds of all species required light for maximum germination. The R:FR value that resulted in 50% of maximum germination varied among species. Water stressed conditions reduced the percentage and rate of germination in all bromeliad species. A. imperialis and P. fl ammea were less sensitive to low water potentials. These contrasting germination requirements among the species studied were related to their habitat preferences.Key words -red:far-red ratio, rupestrian fi elds, seedling morphology, temperature, water potential RESUMO -(Comportamento germinativo de espécies epífi tas e rupícolas de Bromeliaceae do Parque Estadual do Ibitipoca, Minas Gerais, Brasil). Estudou-se o comportamento germinativo de quatro espécies de Bromeliaceae [Alcantarea imperialis (Carrière) Harms, Pitcairnia fl ammea Lindl., Vriesea heterostachys (Baker) L. B. Sm. e Vriesea pendulifl ora L. B. Sm.], oriundas do Parque Estadual do Ibitipoca -MG, com preferências contrastantes de habitat e representando duas formas de vida diferentes. Os objetivos do presente estudo foram: a) caracterizar as sementes quanto ao tipo de germinação e descrever a morfologia do desenvolvimento pós-seminal; b) avaliar o efeito das temperaturas constantes (10 °C a 40 °C) e alternada (20-30 °C); c) da razão vermelho:vermelho-extremo (V:VE) e d) dos diferentes potenciais de água na porcentagem e na velocidade de germinação das sementes. Os resultados demonstraram que todas as espécies produzem sementes pequenas e muito leves, variando de 0,2 a 1,7 mg; a germinação é epígea com plântulas criptocotiledonares e apresentaram valores ótimos de temperatura entre 20 °C e 30 °C. Vriesea heterostachys e V. pendulifl ora foram as únicas que germinaram com sucesso no escuro, mas as sementes das quatro espécies requerem luz para a máxima germinação. Os valores de V:VE que resultaram em 50% da máxima germinação variaram entre as espécies. As condiç...