Managua, due to its tropical climate, varied topography, naturally fertile soils, and abundant rain and water sources, boasts a great variety of flora. Many different types of trees, some of which are not found elsewhere in the world, appear, including ''chilamate''s, ''ceibo''s, ''pochote''s, ''genízaro''s, ''tigüilote''s, royal palms, ''piñuela''s and ''madroño''s (Nicaragua's national tree) surround the city. During the rainy season (May to November), Managua becomes a lush city due to many palms, bushes, and other plants and trees which dominate the city's appearance.