It comes as little surprise that there are only about 600 indigenous plant species in Galapagos. The archipelago has a relatively small land area to begin with about 3,000 square miles.
COASTAL ZONE PLANTS
It has the highest salt tolerant leaves of all the mangroves the leaves and is equipped with special salt-extracting glands. Trees grow to 65 ft (20 m) in height; the long spreading branches are covered by a dark brown bark. The black mangrove has the highest salt equipped with special salt-excreting glands
Red Mangrove is the most common in the Galapagos named for its reddish wood. This species is used around the world as a source of charcoal and tannins for leather working. Trees grow to 72 ft (22 m) in height, yet red mangroves also can be seen as small bushes.
Button Mangrove or Buttonwood is not a true mangrove, yet this tree usually found in the higher mangrove elevations. They have dark gray bark and leave which are either oval, leathery and smooth green or sharply pointed with salt glands at the base. Buttons have green flowers that mature into a round purple fruit.
White Mangrove grows into a shrub with aerial roots close to the water. They thrive in areas with infrequent tidal flooding. Leaves are smooth, oblong and light green in color with notched tips.
Beach Morning Glory
This creeping vine is common on most dune areas. The morning-glory flowers are amongst the largest in the Galapagos Islands. This species is important in stabilising sand dunes.
The saltbush is a sprawling shrub, which often forms dense thickets along shorelines perfect for frigatebird and pelican nesting sites. Some of the Guides will call Cryptocarpus, part of its Latin (scientific) name.
Depending on the season, the sesuvium ground vegetation changes its color from intense green in the rainy season to orange and purple in the dry season. The small, star-shaped flowers are quite distinctive. It is seen near the shore of islands, most notably on South Plaza.
ARID ZONE PLANTS
The candelabra cactus is well-defended with a barrier of spines on its lower stem. The green or red flowers are 1 - 2 inches (2-6 cm), which open before dawn, develop into fruit of the same colors. It is readily observed on the cliffs at Academy Bay, outside the town of Puerto Ayora, Santa Cruz Island.
The lava cactus is considered a "pioneer" or colonizer plant. With bright yellow tipped coloring and microphone shapes, the clumped formations. The plant has soft furry spines and grows in clumps to a height of about two feet (60 cm). New Growth is yellow, turning to brown, which darkens to gray with age. Flowers are white, but last only hours. Lava Cactus can be found on Fernandina, Genovesa, Isabela, Pinta, Santiago and Bartolome Islands.
Prickly Pear Cactus
Prickly Pear Cactus (Opuntia) is the most common cacti in the islands. With its yellow flowers it grows like a shrub, except on islands where herbivores are threat then trunks can grow to 5 ft tall. The Prickly Pear Cactus is the staple of the Land Iguanas & Tortoises' diet. The flat pads of the Opuntia shrubs are also covered with clusters of spines; this armor notwithstanding, the prickly pear pads are a major food and water source of land iguanas as well as tortoises. The yellow flowers develop into an orange-red thorn covered fruit.