Agave (; ; )An Anglo-Hispanic pronunciation. Sunset Western Garden Book, 1995:606–607. is a genus of monocots native to the arid regions of the Americas. The genus is primarily known for its succulent and xerophytic species that typically form large rosettes of strong, fleshy leaves.
Many plants in this genus may be considered perennial, because they require several to many years to mature and flower. However, most Agave species are more accurately described as monocarpic rosettes or multiannuals, since each individual rosette flowers only once and then dies; a small number of Agave species are polycarpic.
Along with plants from the closely related genera Yucca, Hesperoyucca, and Hesperaloe, various Agave species are popular ornamental plants in hot, dry climates, as they require very little supplemental water to survive. Most Agave species grow very slowly. Some Agave species are known by the common name "century plant".
is a Spanish word that refers to all of the large-leafed plants in the Asparagaceae family, including agaves and yuccas. Maguey flowers are eaten in many indigenous culinary traditions of Mesoamerica.
Nomenclature In other regions, it goes by different names. In the Chinese, Japanese, and Korean languages, it is referred to as the compound word dragon tongue orchid (; ; ).
In Malta, it is referred to as Sabbara; In Maltese, Agave americana is referred to as "Sabbara tal-Amerika", and Agave sisalana is referred to as "Sabbara ta' Sisal".
Description
The succulent leaves of most Agave species have sharp marginal teeth, an extremely sharp terminal spine, and are very fibrous inside. The stout stem is usually extremely short, which may make the plant appear as though it is stemless.
Agave rosettes are mostly monocarpic, though some species are polycarpic. During flowering, a tall stem or "mast" ("quiote" in Mexico), which can grow to be high, and Agave salmiana can be significantly taller. The panicle 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). After pollination/fertilization and subsequent fruit development, in monocarpic species, the original rosette dies. However, throughout the lifetime of many Agave species, rhizomatous suckers develop above the roots at the base of the rosette. These suckers go on to form new plants after the original rosette desiccates and dies. Not all agaves produce suckers throughout their lifetimes; some species rarely or never produce suckers, while others may only develop suckers after final maturation with inflorescence. Some varieties can live for 60 years before flowering.
Agaves can be confused with cacti, aloes, or stonecrops, but although these plants all share similar morphological adaptations to arid environments (e.g. succulence), each group belongs to a different plant family and probably experienced convergent evolution. Further, cactus (Cactaceae) and stonecrop (Crassulaceae) lineages are eudicots, while aloes (Asphodelaceae) and agaves (Asparagaceae) are monocots.
Adaptations The agave root system, consisting of a network of shallow rhizomes, allows the agave to efficiently capture moisture from rain, condensation, and dew. In addition to growing from seeds, most agaves produce 'pups' – young plants from runners. Agave vilmoriniana (the octopus agave) produces hundreds of pups on its bloom stalk. Agave leaves store the plant's water and are crucial to its continued existence. The coated leaf surface prevents evaporation. The leaves also have sharp, spiked edges. 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 sap is acidic. Some agaves bloom at a height up to so that they are far out of reach to animals that might attack them. Smaller species, such as Agave lechuguilla, have smaller bloom stalks.
Taxonomy The genus name Agave come from the Ancient Greek from agauós meaning "illustrious, noble" having to do with very tall flower spikes found on its many species.
The genus Agave was erected by Carl Linnaeus in 1753, initially with four species. The first listed was Agave americana, so this became the type species. 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. In the APG II system, Agave was placed in the segregated family Agavaceae. When this system was superseded by the APG III system in 2009, the Agavaceae were subsumed into the expanded family Asparagaceae, and Agave was treated as one of 18 genera in the subfamily Agavoideae, a position retained in the APG IV system of 2016. However, Agavaceae had regained its taxonomic status as an independent family by 2020.
Agaves and close relatives have long presented significant taxonomic difficulty. 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. Within a species, morphological variations can be considerable, especially in cultivation; many named species may be variants of original wild-type species that horticulturalists bred to appear unique in cultivation.
With the advent of DNA sequencing, new karyologic and evolutionary phylogenetic studies showed that the genera Manfreda, Polianthes and Prochnyanthes were genetically nested within the traditional circumscription of Agave, rendering the genus paraphyletic. Early in the 21st century, these new phylogenetic results led to a reclassification and inclusion of Manfreda, Polianthes and Prochnyanthes together as Agave subgenus Manfreda.
There was reaction against the changes from those who noted that the large morphological differences between the genera in this new Agave s.l. making them "counter-intuitive from a horticultural point of view". Manfreda morphologically differs from the classic Agave description in being herbaceous and bulbous, while Polianthes are deciduous with narrow leaves and no spines. Mexican taxonomists have continued to adhere to the traditional classifications and have published new species of Polianthes.
Thus, based on a wider consideration of previously established genetic, morphological, and estimated genetic divergence times, Vázquez-García et al. proposed a narrower circumscription of Agave s.str. by creating three new genera: Echinoagave, Paleoagave and Paraagave. These new genera have gained some acceptance, and pave the way for a reconsideration of Manfreda, Polianthes and Prochnyanthes.
Commonly grown species
Some commonly grown species include Agave americana, A. angustifolia, A. attenuata, A. murpheyi, A. palmeri, A. parryi, A. parviflora, A. tequilana, A. victoriae-reginae, and A. vilmoriniana.
In the UK the Plant Heritage collection is held by Ian Mills of Harold Wood in Essex, with 123 species, 76 cultivars and 217 taxa.
A. americana
One of the most familiar species is A. americana, a native of tropical America. Common names include century plant, maguey (in Mexico), or American aloe (though not related to the genus Aloe). The name "century plant" refers to the long time the plant takes to flower. The number of years before flowering occurs depends on the vigor of the individual plant, the richness of the soil, and the climate; during these years, the plant is storing in its fleshy leaves the nourishment required for the effort of flowering.
A. americana, century plant, was introduced into southern Europe about the middle of the 16th century and is now naturalized as well as widely cultivated as an ornamental, as it is in the Americas. In the variegated forms, the leaf has a white or yellow marginal or central stripe. As the leaves unfold from the center of the rosette, the impression of the marginal spines is conspicuous on the still erect younger leaves. The plant is reported being hardy to −9.5 to −6.5 °C or Zone 8b 15-20f. Being succulents, they tend to rot if kept too wet. In areas such as America's Pacific Northwest, they might be hardy for cold winter temperatures, but need protection from winter rain. They mature very slowly and die after flowering but are easily propagated by the offsets from the base of the stem.
A. americana (a blue variety) occurs in abundance in the Karoo, and arid highland regions of South Africa. Introduced by the British settlers in 1820, the plant was originally cultivated and used as emergency feed for livestock. Today, it is used mainly for the production of syrup and sugar.
A. attenuata
A. attenuata is a native of central Mexico and is uncommon in its natural habitat. Unlike most species of agave, A. attenuata has a curved flower spike from which it derives one of its numerous common names – the foxtail agave. It is also commonly grown as a garden plant. Unlike many agaves, A. attenuata has no teeth or terminal spines, making it an ideal plant for areas adjacent to footpaths. Like all agaves, it is a succulent and requires little water or maintenance once established, but cannot withstand frost.Agave attenuata , The Lovely Plants
A. tequilana
Agave azul (blue agave) is used in the production of tequila. It is native to the Caribbean as well as many regions of Mexico like Colima, Nayarit, Jalisco and more. In 2001, the Mexican government and European Union agreed upon the classification of tequila and its categories. All 100% blue agave tequila must be made from the A. tequilana 'Weber's Blue' agave plant, to rigorous specifications and only in the state of Jalisco. Blue agave is significantly different from other types of agave because it is higher in fructose and much sweeter compared to the rest. It is therefore the primary source for agave syrup, a nectary sweetener made for consumption.
Ecology Agave species are used as food plants by the larvae of some Lepidoptera (butterfly and moth) species, including Batrachedra striolata, which has been recorded on A. shawii.
Toxicity Some species contain components in their juice which can cause dermatitis for some people.
Uses
The ethnobotany of the agave was described by William H. Prescott in 1843:William H. Prescott,1843 (1979 reprint). History of the Conquest of Mexico and the Conquest of Peru, Modern Library, pp. 79–80
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. The agave, in short, was meat, drink, clothing, and writing materials for the Aztec! 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 sap of some species can also be used as soap.
Food and fiber