This zone contains the main nesting sites of the nearly extinct Puerto Rican parrot, which nests in hollow trunks of cyrilla trees. Most trees are evergreen and over 150 species occur. Many epiphytic ferns, bromeliads, and orchids are common. Many trees in this zone are drought deciduous, as a result of periods of low rainfall in January through April. This forest is prevalent along the southwest coast and on most neighboring islands, including the Virgin Islands.
Vegetation is mostly drought deciduous.
Palms are absent, but cacti, thorny legumes, grasses, and short trees with flattened crowns are common. The growing season lasts for 365 days. Surface Water Characteristics. Compiled by Southern Region. Cacti and thorny legumes are characteristic vegetation of the tropical dry forest along the southwestern coast and on some islands.