Yucca

Yucca is a genus of perennial shrubs and trees in the family Asparagaceae, subfamily Agavoideae. Its 40–50 species are notable for their rosettes of evergreen, tough, sword-shaped leaves and large terminal panicles of white or whitish flowers. They are native to the Americas and the Caribbean in a wide range of habitats, from humid rainforest and wet subtropical ecosystems to the hot and dry (arid) deserts and savanna.

Early reports of the species were confused with the cassava (Manihot esculenta). Consequently, Linnaeus mistakenly derived the generic name from the Taíno word for the latter, yuca. The Aztecs living in Mexico since before the Spanish arrival, in Nahuatl, call the local yucca species (Yucca gigantea) iczotl, which gave the Spanish izote. Izote is also used for Yucca filifera.

Distribution
The natural distribution range of the genus Yucca (49 species and 24 subspecies) covers a vast area of the Americas. The genus is represented throughout Mexico and extends into Guatemala (Yucca guatemalensis). It also extends to the north through Baja California in the west, northwards into the southwestern United States, through the drier central states as far north as southern Alberta in Canada (Yucca glauca ssp. albertana).

Yucca is also native northward to the coastal lowlands and dry beach scrub of the coastal areas of the southeastern United States, along the Gulf of Mexico and South Atlantic States from coastal Texas to Maryland.

Yuccas have adapted to an equally vast range of climatic and ecological conditions. They are found in rocky deserts and badlands, in prairies and grassland, in mountainous regions, woodlands, in coastal sands (Yucca filamentosa), and even in subtropical and semitemperate zones. Several species occur in humid tropical zones (Yucca lacandonica) but most species occur in arid conditions, with the deserts of North America being regarded as the center of diversity for the genus.

Ecology
Yuccas have a very specialized, mutualistic pollination system; being pollinated by yucca moths (family Prodoxidae); the insect transfers the pollen from the stamens of one plant to the stigma of another, and at the same time lays an egg in the flower; the moth larva then feeds on some of the developing seeds, always leaving enough seed to perpetuate the species. Certain species of the yucca moth have evolved antagonistic features against the plant. They do not assist in the plant's pollination efforts while continuing to lay their eggs in the plant for protection.

Yucca species are the host plants for the caterpillars of the yucca giant-skipper (Megathymus yuccae), ursine giant-skipper (Megathymus ursus), and Strecker's giant-skipper (Megathymus streckeri). Beetle herbivores include yucca weevils, in the Curculionidae.

Uses
Yuccas are widely grown as ornamental plants in gardens. Many species also bear edible parts, including fruits, seeds, flowers, flowering stems, and (more rarely) roots. References to yucca root as food often arise from confusion with the similarly pronounced, but botanically unrelated, yuca, also called cassava or manioc (Manihot esculenta). Roots of soaptree yucca (Yucca elata) are high in saponins and are used as a shampoo in Native American rituals. Dried yucca leaves and trunk fibers have a low ignition temperature, making the plant desirable for use in starting fires via friction. The stem (when dried) that sports the flowers is often used in conjunction with a sturdy piece of cedar for fire-making. In rural Appalachian areas, species such as Yucca filamentosa are referred to as "meat hangers". With their sharp-spined tips, the tough, fibrous leaves were used to puncture meat and knotted to form a loop with which to hang meat for salt curing or in smokehouses. The fibers can be used to make domestic items or for manufacturing cordage, be it sewing-thread or rope. Yucca extract is also used as a foaming agent in some beverages such as root beer and soda. Yucca powder and sap are derived from the logs of the plant; such extracts can be produced by mechanical squeezing and subsequent evaporation of the sap, and are widely used in food, cosmetics, and pharmaceuticals

Gastronomy
The flower petals are commonly eaten in Central America, but the plant's reproductive organs (the anthers and ovaries) are first removed because of their bitterness. The petals are blanched for 5 minutes, and then cooked a la mexicana (with tomato, onion, chili) or in tortitas con salsa (egg-battered patties with green or red sauce). In Guatemala, they are boiled and eaten with lemon juice.

In El Salvador, the tender tips of stems are eaten and known locally as cogollo de izote.

Cultivation
The most common houseplant yucca is Yucca gigantea.

Yuccas are widely grown as architectural plants providing a dramatic accent to landscape design. They tolerate a range of conditions but are best grown in full sun in subtropical or mild temperate areas. In gardening centres and horticultural catalogues, they are usually grouped with other architectural plants such as cordylines and phormiums.

Several species of yucca can be grown outdoors in temperate climates, including:-


 * Yucca filamentosa
 * Yucca flaccida
 * Yucca glauca
 * Yucca gloriosa
 * Yucca recurvifolia
 * Yucca rostrata

Symbolism
The yucca flower is the state flower of New Mexico in the southwest United States. No species name is given in the citation; however, the New Mexico Centennial Blue Book from 2012 references the soaptree yucca (Yucca elata) as one of the more widespread species in New Mexico.

The Yucca flower is also the national flower of El Salvador, where it is known as flor de izote.

Species
, the World Checklist of Selected Plant Families recognizes 49 species of Yucca and several hybrids:

A number of other species previously classified in Yucca are now classified in the genera Dasylirion, Furcraea, Hesperaloe, Hesperoyucca, and Nolina.

Cultivars
From 1897 to 1907, Carl Ludwig Sprenger created and named 122 Yucca hybrids.