St. Peter and St. Paul Rocks

The Araya and Paria xeric scrub stretches along Venezuela's northeastern Caribbean coast, covering the Araya and Paria peninsulas, the area around Cumaná, and the offshore islands of Margarita, Coche, and Cubagua. Its vegetation is a mosaic of salt-tolerant dune herbs, dry thorn scrub studded with columnar and prickly-pear cacti such as Stenocereus and Opuntia, and low deciduous woodland with trees including Bursera, Prosopis, and Parkinsonia, grading into semi-deciduous and evergreen forest on the higher hills. The climate is hot and markedly arid, with average temperatures around 24 to 27 degrees Celsius and rainfall that is very sparse on the Araya Peninsula but much higher on the wetter Paria slopes. The ecoregion harbors notable wildlife, most famously the threatened yellow-shouldered amazon parrot, alongside breeding sea turtles and a number of endemic plants, yet it is considered critically threatened by overgrazing, deforestation, sand extraction, and coastal urbanization. For gardeners in hot, dry climates, several drought-hardy genera native here, including the cacti Stenocereus and Opuntia and the flowering tree Parkinsonia, are widely grown as ornamentals.

The Atacama Desert ecoregion runs as a continuous strip for nearly 1,000 kilometers along the narrow coast of the northern third of Chile, extending toward southern Peru, within the Neotropic realm. Its interior is one of the driest places on Earth and almost without vegetation, while life concentrates on coastal slopes and ravines where Pacific fog and winter drizzle sustain isolated oases known as lomas. Characteristic plants include columnar and cushion cacti such as Eulychnia, Copiapoa, Browningia, and Leucostele, alongside bromeliads on sandy ground and the endemic tamarugo tree, with around 550 species of ferns, gymnosperms, and flowering plants recorded. Endemism here can exceed 60 percent, and the desert is the largest fog desert on the planet, supporting a sparse but highly adapted fauna whose flagship is Darwin's leaf-eared mouse. For gardeners, several of its hardy succulents, notably Copiapoa cacti, are prized ornamentals well suited to arid, low-water plantings.

The Caribbean Shrublands ecoregion is a Neotropic strip of xeric scrub scattered across the low, dry islands of the Caribbean, including the Cayman Islands, all of Barbados, the coastal Windward Islands (parts of Grenada, St. Lucia, Martinique, Dominica, and Trinidad), and much of the Leeward Islands, from Guadeloupe's Grande-Terre and Marie-Galante to Antigua, Anguilla, St. Martin, St. Barthélemy, and the eastern Virgin Islands. Its vegetation is seral in character, grading from herbaceous coastal strand through scrublands and savannas to littoral woodland, and it sits within a broader island setting of tropical dry forests and mangroves. The climate is warm and tropical, with the Cayman Islands experiencing a humid regime, a distinct wet season from May to November, and persistent trade winds. The ecoregion holds notable island endemism: the Cayman Islands alone support 26 herpetofauna species, about three-quarters of them endemic, while the critically endangered Grenada dove, Grenada's national bird, persists in mature dry scrub lowlands and hillsides. Habitat loss and introduced species are the leading threats to these naturally limited coastal scrub habitats.

The Cuban cactus scrub is a xeric shrubland ecoregion strung along the leeward, southeastern coast of Cuba, concentrated in the provinces of Guantanamo and Santiago de Cuba and covering roughly 3,300 square kilometers. Its vegetation is dominated by columnar cacti and other succulents alongside palms, organized into coastal scrubland zones rooted in shallow rendzina soils derived from coralline limestone; characteristic woody genera include Bursera, Croton, Acacia, and Cordia. The climate is semidesert, receiving less than 800 mm of rainfall a year with a prolonged dry period and average temperatures near 26 degrees Celsius. The ecoregion is an important center of plant diversity and endemism, sheltering endemic reptiles such as the Cuban rock iguana along with the flagship Cuban flower bat, a key pollinator of its native flora. For gardeners working hot, dry coastal sites, the region is home to drought-hardy ornamental cactus genera native here, including Opuntia, Harrisia, Pilosocereus, Melocactus, and Leptocereus.

The Galápagos Islands xeric scrub covers Ecuador's Galápagos archipelago, roughly 128 volcanic islands scattered across the Pacific some 960 km west of the South American mainland. Across the lowland arid zone the vegetation is drought-tolerant scrub and dry forest, characterized by palo santo (Bursera graveolens), the endemic guayabillo (Psidium galapageium), coastal saltbush (Cryptocarpus pyriformis) and Maytenus, and several endemic cactus genera including the tree-like prickly pears (Opuntia), Jasminocereus, and Brachycereus. The climate is semi-arid and oceanic with two seasons: a warm wet season from about December to May and a cooler, drier garúa season, while rainfall climbs sharply with elevation so that higher slopes carry moister Scalesia woodlands. The islands hold around 500 native vascular plant species, roughly 180 of them endemic, and the ecoregion is the celebrated home of the giant Galápagos tortoise and an emblem of evolutionary endemism. Its native flora is now critically threatened by introduced and invasive species, including goats and numerous non-native plants, though nearly the entire ecoregion lies within Galápagos National Park.

The Guajira-Barranquilla xeric scrub is an arid shrubland ecoregion strung along the Caribbean coast of Colombia and Venezuela, occupying the Guajira Peninsula and the Ranchería river valley and reaching out to the ABC Islands of the Leeward Antilles. Its dry lowlands are dominated by thorny trees and succulents, with characteristic genera including Acacia, Prosopis (mesquite), and a wealth of cacti such as Opuntia. The climate is hot and dry, with low and highly variable annual rainfall and warm temperatures year-round, a pocket of true xerophytic vegetation within the otherwise wet Neotropics. The region is notable as habitat for a large community of Caribbean flamingo (Phoenicopterus ruber) alongside a diversity of birds and bats, and much of the Serranía de Macuira is protected within Macuira National Park. For gardeners drawn to drought-tolerant plantings, the Los Flamencos Sanctuary here is recognized as a center of plant diversity for Salvia, the bromeliad Hechtia, and native cacti.