Poikilacanthus macranthus (Acanthaceae), like many shrubs in the neotropical cloud forest of Monteverde, Costa Rica, is capable of regeneration through stem and twig fragments. Our field sampling indicated that reproduction in P. macranthus is primarily through fragmentation in the Monteverde region. Random amplified polymorphic DNAs (RAPDs) were employed to examine clonal diversity in four populations of P. macranthus, and two primers yielded 11 variable markers that were used to identify genets. Sixty-eight multilocus genotypes were identified out of 277 plants sampled. Clonal diversity values were higher than the average for clonal plant species, as the number of genets per ramet was 0.25, while the mean D value was 0.87 and the mean E value was 0.84.