The Cytology of <i>Lachenalia</i>

Abstract

1. Twenty-one species and varieties of Lachenalia examined showed four different basic numbers x=7, 8, 11 and 13. A polyploid series 3n, 4n and 6n occurs with the basic number 7.2. The somatic chromosomes are of unusual shapes, frequently tapering towards the ends. Certain chromosome resemblances are traced between species with different basic numbers. Chromosome morphology indicates that the higher basic numbers have not arisen by fragmentation of chromosomes.3. The higher basic numbers are therefore perhaps derived from the lower, as secondarily balanced numbers. Probably this is the most frequent mode of origin of new basic numbers in a genus. Secondarily balanced basic numbers may arise by the formation of a polyploid series in the original number, followed by interspecific hybridisation between different polyploids.