Chromosome number of 2n=18 is reported for P. tarminiana, a new species of Passiflora (subgenus Tacsonia). Several meiotic irregularities were observed, such as presence of univalents, asynchrony in chromosome migration, chromosome bridges, micronuclei and cytoplasm degeneration. Pairing of chromosomes of different size and chromosome secondary association in metaphase 1 also occurred. Micronucleus in prophases and telophases, and chromosome elimination are reported for the first time in Passiflora. Different relative positions of spindles were observed, leading to different tetrad patterns. Pollen staining indicated a high fertility. Reintegration of asynchronous chromosomes in the nucleus and early elimination of unbalanced microsporocytes can explain the absence of correlation between the frequency of irregularities and pollen stainability.