Root formation in cuttings of two species of Calliandra (Leguminosae - Mimosoideae)

ABSTRACT

Calliandra brevipes and Calliandra tweedii, known as 'caliandra' or 'esponjinha', are native Brazilian ornamental species. This experiment aimed to evaluate the effect of the application of different concentrations of Indolbutiric acid (IBA) in root formation of both species by observing anatomical structure. Both species presented an increase in root formation percentage and number of new roots when treated with IBA. All Calliandra brevipes treatments achieved higher root formation percentages than Calliandra tweedii. The best results of C. brevipes were 2000 mg.L^-1 IBA (56,67%). C. brevipes had 90% of rooting without IBA application. Roots originated directly for both species, either from the inner or outer phloem region. Probably the limiting factors for C. tweedii root formation were linked to its anatomy and physiology, such as the absence of starch granules in the medular region.

Key words: plant cuttings; plant anatomy; vegetative propagation; ornamental plants; caliandra