THE NEOTROPICAL ANGIOSPERM FAMILIES BRUNELLIACEAE AND CARYOCARACEAE - 1ST KARYO-SYSTEMATICAL DATA AND AFFINITIES

Chromosome numbers are polyploid, 2n = 28 in Brunellia comocladiifolia and B. mexicana and 2n = 46 in Caryocar brasiliense, C. microcarpum and C. villosum. The chromosome are small in both genera, with a length of .apprx. 1.6-0.4 .mu.m. Interphase nuclei correspond to the prochromosomal and the chromocentric type, respectively. This agrees with the systematic placement of Brunelliaceae into Cunoniales and of Caryocaraceae into Theales. Brunellia exhibits affinities to various other orders of Rosidae (and Hamamelididae) and is suggested to be primarily apetalous. On a comparative basis, the chromosome numbers found in both families are interpreted as paleopolyploid (4x and 6x). This apparently corresponds with their rather primitive features, systematic isolation, relatively depauperate status and evidently great age.