Xerophytes are plants that are adapted for arid environments. Common xerophytic features include: succulent tissues that store water and organic acids, photosynthetic stems with reduced surface area, waxy cuticles to limit water loss, sharp spines, reflective hairs, and underground tubers. Xerophytism is an example of evolutionary convergence, in which distinctly dissimilar ancestors give rise to similar descendants through selection for a common set of features.
CACTUS FAMILY (Cactaceae, stem succulents. North, Central and South America)
With one exception, cacti inhabit only the Americas. They are highly adapted to growing in desert environments. Cacti are fleshy stems with spines (highly modified leaves) that offer protection against herbivores.
(Crassulaceae, worldwide distribution, many CAM species)
The family has no important agricultural crops, but several taxa are grown horticulturally and used in rock gardens.
SPURGE FAMILY (Euphorbiaceae, worldwide distribution)
Poisonous diterpene esters and lectins are widely present in the family. The milky latex released by plants can blister skin, blind eyes, and can cause vomiting if ingested. Also an important source of natural rubber and oil.
ICE PLANT FAMILY (Aizoaceae. Mostly native to Africa.)
Succulent leaves with bladder-like cells in the epidermis is characteristic of the family.
Family includes succulent ornamental genera Aloe, Gasteria and Haworthia.
DOGBANE FAMILY (Apocynaceae including subfamilies Asclepiadoideae, Rauvolfioideae)
Worldwide distribution. Some taxa such as Carrion flowers [Stapelia] emit the scent of rotting flesh to attract pollinators, while others like Frangipani [Plumeria] emit a sweet aroma to attract moths.
ASTER FAMILY (Asteraceae)
OTHER FAMILIES (Asparagaceae, Zamiaceae, Acanthaceae)