Life-form spectra are known to vary greatly among different biomes, being largely defined by macroclimates on a global scale. Benign climates usually have biomes with a large proportion of phanerophytes, whereas harsher climates favor life-forms with greater degrees of bud protection. We sampled the flora of a semideciduous Atlantic forest and classified each recorded species in one of the Raunkiaerian life-forms. We then compared the biological spectrum of this seasonal forest with other published spectra of the main Brazilian biomes. We show that each biome has a clear functional spectrum and that the semideciduous Atlantic forest is to some extent functionally similar to Amazonian and Atlantic ombrophilous forests. The relatively moist semideciduous and the ombrophilous forests have biological spectra dominated by phanerophytes. The fire-prone, seasonal “Cerrado” savannas have spectra dominated by both phanerophytes and hemicryptophytes. However, the spectra of the semiarid “Caatinga” woodlands seem to depend on soil type: woodlands on crystalline terrains are dominated by therophytes, whereas those on sedimentary terrains are dominated by both phanerophytes and therophytes. Sedimentary caatingas have spectra whose features are in an intermediate position between those of crystalline caatingas and moist forests. On a continental scale, macroclimate seems to be the most important environmental factor separating different biological spectra, but wildfires in the “Cerrado” and soil differences between crystalline and sedimentary Caatinga woodlands also play an important role in defining the local spectrum on a regional scale.