Occasional, especially in the young forest. Flowers from April to October, mostly from June to September; plants may flower only once every two years. The fruits mature mostly from June to December. Plants have been seen replacing their leaves over a short span of time in the late dry season. Probably the most variable Zanthoxylum on the island, especially in terms of leaf shape. Some BCI plants have consistently much smaller leaflets than others, and additional morphological and phenological study may show them to be distinct species. Plants of the small-leaved form generally flower and fruit ahead of those with larger leaves, although the seasons overlap. This is further evidence that two taxa may be involved in what is being called Z. panamense. The small-leaved plant corresponds with the type. The prickles on the trunk may be hollow and are often inhabited by ants. Costa Rica and Panama. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Colon, Chiriqui, Panama, and Darien.