Clonal strategies of a woody weed: Melia azedarach

Melia azedarach L., a weedy tree that typically reproduces by seeds, may exhibit clonal growth following disturbance (e. g. fire, herbivory, animal injury). A dynamic and holistic study (sensu Hallé et al., 1978) was carried out in order to determine the architecture and the vegetative growth strategies, in plants collected from undisturbed and disturbed areas in the 'El Palmar' National Park. The architectural and morphological observations can be summarized as follows: (a) Tree architecture is determined by a monopodial trunk that produces tiers of orthotropic monopodial branches, (b) The root system consists of a tap root with woody primary lateral roots that exhibit plagiotropic growth and are typically found within the first few centimeters (ca. 4 cm) of the soil profile, (c) Root buds were produced in all (fire treated and control) plagiotropic root cuts when incubated under controlled conditions. Root suckers developed from the differentiation of parenchymatous cells produced by meristematic activity in the cambial zone. The ecological implications of vegetative reproduction on the invasive capacity of this species are discussed.