The genus is primarily known for its succulent and xerophytic species that typically form large rosettes of strong, fleshy leaves.

[7] Maguey is a Spanish word that refers to all of the large-leafed plants in the Asparagaceae family,[citation needed] including agaves and yuccas.

[5]: 30  During flowering, a tall stem or "mast" ("quiote" in Mexico), which can grow to be 12 metres (40 feet) high,[8] grows apically from the center of the rosette and bears a large number of short, tubular flowers and sometimes vegetatively produced bulbils (a form of asexual reproduction).

[9] Further, cactus (Cactaceae) and stonecrop (Crassulaceae) lineages are eudicots, while aloes (Asphodelaceae) and agaves (Asparagaceae) are monocots.

The spikes discourage predators from eating the plant or using it as a source of water and are so tough that ancient peoples used them for sewing needles.

The genus name Agave come from the Ancient Greek αγαυή agauê from ἀγαυός agauós meaning "illustrious, noble"[10][11] having to do with very tall flower spikes found on its many species.

[2] In the Cronquist system and others, Agave was placed in the family Liliaceae, but phylogenetic analyses of DNA sequences later showed it did not belong there.

These difficulties could be due to the relatively young evolutionary age of the group (major diversification events of the group most likely occurred 8–10 million years ago), ease of hybridization between species (and even genera), incomplete lineage sorting, and long generation times.

Some commonly grown species include Agave americana,[18] A. angustifolia, A. attenuata, A. murpheyi, A. palmeri, A. parryi, A. parviflora, A. tequilana, A. victoriae-reginae, and A. vilmoriniana.

A. americana (a blue variety) occurs in abundance in the Karoo, and arid highland regions of South Africa.

Unlike many agaves, A. attenuata has no teeth or terminal spines, making it an ideal plant for areas adjacent to footpaths.

[23] The ethnobotany of the agave was described by William H. Prescott in 1843:[24] But the miracle of nature was the great Mexican aloe, or maguey, whose clustering pyramids of flowers, towering above their dark coronals of leaves, were seen sprinkled over many a broad acre of the table-land.

As we have already noticed its bruised leaves afforded a paste from which paper was manufactured, its juice was fermented into an intoxicating beverage, pulque, of which the natives, to this day, are extremely fond; its leaves further supplied an impenetrable thatch for the more humble dwellings; thread, of which coarse stuffs were made, and strong cords, were drawn from its tough and twisted fibers; pins and needles were made from the thorns at the extremity of its leaves; and the root, when properly cooked, was converted into a palatable and nutritious food.

Surely, never did Nature enclose in so compact a form so many of the elements of human comfort and civilization!

The four major edible parts of the agave are the flowers, the leaves, the stalks or basal rosettes, and the sap (in Spanish: aguamiel, meaning "honey water").

The agave, especially A. murpheyi, was a major food source for the prehistoric indigenous people of the Southwestern United States.

[26] In southern California and the Baja California Peninsula, the roasted hearts of A. shawii and A. deserti were historically among the most important foods for the Cahuilla, Kumeyaay, Kiliwa, and Paipai peoples, leaving ubiquitous archeological evidence in the form of agave-roasting pits throughout the region.

[citation needed] During the development of the inflorescence, sap rushes to the base of the young flower stalk.

[30][31] Agave contains fructooligosaccharides, which are naturally occurring oligosaccharides that support safely subjecting peanut-allergic people to allergen immunotherapy.

[32] Resulting from its natural habitat in stressful environments, agave is under preliminary research for its potential use in germplasm conservation and in biotechnology to better anticipate the economic effects of global climate change.