This article is about the genus comprising species of perennials, shrubs, and trees. For the species of root vegetable sometimes called "yuca", seeCassava. For other uses, seeYucca (disambiguation).
Yucca (/ˈjʌkə/YUCK-uh) is both thescientific name andcommon name for a genus native to North America fromPanama to southern Canada. It contains 50 accepted species. In addition to yucca, they are also known asAdam's needle orSpanish-bayonet. The genus is generally classified in theasparagus family ina subfamily with theAgave, though historically it was part of thelily family. The species range from small shrubby plants to tree-like giants, such as theJoshua tree. All yuccas haverosettes of leaves that taper to points and inflorescences with many flowers that are mainly cream white with thick petals. Though adapted to a wide range of climates the plants arexerophytes, ones that specialize in dry living conditions.
The tight relationship between the yucca plants and their pollinators, the yucca moths from the generaTegeticula andParategeticula, is a well known example of evolutionarymutualism. They are an important part of the ecology of North Americandeserts, providing shelter to small animals and creating habitats. The human uses of yuccas includegarden plants, as food, and forextracts. The flower petals of various species are eaten as a part of local cuisine, particularly inCentral America and Mexico. Historically, the yucca was extensively used for its fibers to make cords, baskets, mats, and sandals. It continues to be used by native peoples for traditional soaps.
Yuccas areperennial plants with long, pointed sword shaped leaves in one or more rosettes, circular arrangements of leaves. Usually the leaves are stiff and fibrous, but a few species have fleshy leaves.[2] The leaves are numerous and arranged in spirals at the ends of stems or branches.[3] Plants can be small shrubs or large resembling trees.[4] The surface of the leaves are hairless, but some have a very rough surface. About half of all species have fibers that peel off the edges of the leaves. Their color can be bright green, gray-green, or pale blue.[5] The leaves never have spines on their edges, but may be very finely toothed.[6] Some yucca species reproduce by undergroundrhizomes and form colonies of plants,[7] but this feature is rare in the fleshy-fruited yuccas, which will usually produce new sprouts at the base of the plant from nodule-like growths.[8]
Plants without stems or trunks grow from a thick undergroundcaudex, a modified stem with growth at the end like in a palm tree.[9] Species that do not have trunks tend to be found in colder areas such as theRocky Mountains,Great Plains, and eastern United States. Species with trunks are more common in the subtropics, deserts, and tropics to the south.[7] The largest of these tree yuccas isYucca brevifolia, commonly known as theJoshua tree in the American southwest.[10] The Joshua tree can reach up to 15 meters (49 ft) in height.[11] Every species grows in soil, except forYucca lacandonica, which grows as anepiphyte.[12]
Some species have ascape, a long flowering stem without any leaves or bracts along its length. These are always less than 2.5 centimeters (1 in) in diameter. Theinflorescence is usually upright, but in a few species bends over and hangs downward. The inflorescence can be apanicle, where the flowers are on branches off the main stem, or araceme, where the flowers are attached directly by flower stalks to the main stem.[2] Though the plants live for many years and flower multiple times, each inflorescence dies after setting seed.[12]
The flowers are large and showy, ranging from bell shaped to round like a globe.[4] The sixtepals are white to cream or slightly green in color.[12] They are thick and leathery in texture, and in many species the three outermost tepals will have red, pink, maroon, purple, or brown streaks.[13]
In about half of the species the fruit is a drycapsule. In the other half, it is a fleshy fruit. Inside the fruit, the seeds are tightly packed, flat, and black in color.[14] Dry capsules are held in an upright position while soft capsules hang downwards.[4]
Due to similar characteristics of many species it is difficult to identify them without flowers or fruits. Many characteristics taken together are needed to make identifications, often including the size and color of thepistil,style, and flowers while alive.[15] Yuccas are distinct fromAgave due to typically having less succulent leaves, thicker flower petals, and a lack of spines on leaf edges.[6]
In 1902William Trelease published a paper separating outClistoyucca andSamuela fromYucca,[2] along with his 1893 separation ofHesperoyucca from the genus.[17]Susan Delano McKelvey argued against this separation, though she recognized them as sections ofYucca. McKelvey did allow thatHesperoyucca might be recognized as a genus writing, "since a number of flower and fruit characters differ from those in all other sections". DNA investigations in the 1990s found support forHesperoyucca.[2] As of 2025,Hesperoyucca is listed as accepted.[17]
Prior to the 1950sYucca was placed inLiliaceae, the lily family, due to having asuperior ovary. Since that time, evidence of it being more closely related to theAgave genus has been accepted.[18] In particular, the discovery thatYucca, like plants inAgave, has 5 large and 20 smallchromosomes was a large factor in reconsidering their relationship.[19] TheAPG III system, published in 2009, placed the genus into the familyAsparagaceae in theAgavoideae subfamily.[20] This classification continued inAPG IV.[21] However, some botanists prefer to classify this subfamily as a family named Agavaceae.[18]
In 1737 Linnaeus, in setting out his rules for the names of genera, wrote, "Generic names which have not a root derived from Greek or Latin are to be rejected".[28] However, in the case ofYucca and several other names, he violated his own rule by adopting names derived from other languages.[29] The word was borrowed from theCarib language by Spanish asjuca, starting withAmerigo Vespucci in 1497 referring tocassava.[30] It was first used to refer to the unrelated plants of the genusYucca in a German travel account published in 1557.[12] This was used as the genus name by Linnaeus inSpecies Plantarum.[2][1]
The nameyucca is used as an Englishcommon name for plant species in the genus. It is pronounced/ˌˈjəkəˌ/ (YUCK-uh) in bothBritish English andAmerican English, but may also be pronounced/ˌˈjuːkəˌ/ (YOO-kuh) in British English.[30] It is also known asAdam's needle or asSpanish-bayonet.[30][2] Other common names for some species includeSpanish dagger,shin dagger,soapweed, orsoaptree.[30][4] In the plant trade they are sometimes known aspalm lilies.[31] The name yucca can be confused with cassava, though the spellingyuca is often used to distinguish the food from plants inYucca.[30]
The Aztecs living in Mexico call the local yucca speciesiczotl inNahuatl, which gave the Spanishizote.[32]
The natural range of the yuccas stretches across much of southern North America from Panama in the south as far north as Alberta in Canada.[1] The exact extent is disputed as thoughYucca gigantea is listed byPlants of the World Online (POWO) andWorld Flora Online (WFO) as native to Central America,[1][22] other sources like World Plants list it as introduced to all the nations of Central America.[33] Likewise,Yucca flaccida is listed as native toOntario by POWO, WFO, and World Plants,[1][22][33] but is listed by the Database of Vascular Plants of Canada as introduced.[34]
Yuccas are generally accepted to be introduced to the islandsCaribbean.[1][22] Various species have also escaped from cultivation in Europe as far east as Poland and Romania. They grow as an introduced species in Turkey, Pakistan, and Bangladesh in Asia. In Africa they are reported in Tunisia andKwaZulu-Natal andFree State in South Africa. They have been introduced to South America in Ecuador, Bolivia, Uruguay, and Argentina.[1] In AustraliaAloe yucca (Yucca aloifolia) has naturalized inWestern Australia,Queensland,New South Wales, and theAustralian Capital Territory. It is doubtfully naturalized onLord Howe Island and naturalized onNorfolk Island.[35] Two other species,Yucca gloriosa andYucca whipplei, may also be naturalized in Australia.[36][37] They are listed as anenvironmental weed in New Zealand having been found 31 times outside of cultivation.[38]
The yuccas arexerophytic, plants with adaptations to dry environments, with even those native to rainy habitats growing better when in drier areas.[39] The smaller, freeze-tolerant species of yucca have two centers of diversity, one in Texas and the other on theColorado Plateau. They are found generally to the north and east of the range inChihuahuan Desert, theTrans-Pecos region, theRocky Mountains, theColorado Plateau, and theGreat Plains. Tree-like yuccas with fleshy fruits have a center of diversity in theSonoran Desert. They are found mainly in Mexico, while the tree like yuccas with spongy fruits are found only in theMojave Desert.[40]
Yuccas have a very specializedmutualistic system ofpollination.[41] Yucca moths in genusTegeticula orParategeticula pollinate the flowers and then lay their eggs in the seed capsules of yuccas.[42] Some species ofTegeticula provide no benefit to the yuccas, laying eggs but not pollinating the flowers due to lacking the specialized parts for carrying pollen.[43] Almost all species are pollinated by one or more species of these moths with one species,Aloe yucca (Yucca aloifolia), documented to revert away from mutualism to a generalist pollinator when the moths are absent.[44][45] This mutualism was first documented byCharles Valentine Riley in 1873,[46] and its discovery elicited much excitement in the scientific community. In a 1874 letter to his friendJoseph Dalton Hooker,Darwin called it "the most wonderful case of fertilisation ever published".[47]
Instances of animal behavior that are exclusively aimed at pollination of plants, rather than just accompanying the animal gathering food, are quite rare. Female yucca moths have tentacle-like mouth parts that they use to gather pollen and then to deposit it on the reproductive parts.[42] In the 150 years following the discovery of this relationship it became one of the most famous of the documented plant and animal mutualisms along with thefig wasps andfig trees.[48] The association between the yuccas and the yucca moths is quite ancient, with amolecular clock estimate that it began between 51.3 and 31.7 million years ago with them becoming pollinators 35.6 million years ago ±9 million years.[49]
About two-thirds of the moth species are limited to just one species of yucca. There is some evidence that the moths that visit a single species are guided to the flowers by distinct scents. All yucca moths species gather together inside of blooms to mate. The females ofTegeticula gather pollen and then pierce the yucca ovaries or styles to lay their eggs. After this, they deposit their load of pollen to ensure the development of seeds. The femaleParategeticula moths cut grooves intoflower stems, petals, or other parts to lay their eggs, but also use their mouthparts to deposit pollen onstigmas and intostyles.[42] In order to limit the numbers of seeds eaten by moth larvae, yucca plants abort fruits with large numbers of eggs deposited within them, but also drop fruits without sufficient pollination produce minimal number of seeds.[50]
Though the reduction or local extinction of yucca moths can reduce the fertility of seeds or the numbers produced, there is not yet evidence that it reduces the populations of yuccas as they are relatively long lived.[51] The scientist Robert William Cruden and his collaborators speculated in 1976 that yucca species are limited to lower elevations by the inability of their moth pollinators to tolerate colder temperatures at high elevations.[52] Yuccas continue to be an important subject of study because of the simplecoevolutionary competition and their relatively exclusive relationship.[53]
Larva of a yucca giant-skipper butterfly on a yucca leaf in Florida
Besides the yucca moths, a number of other insect species depend upon yuccas for food.[54] Thebogus yucca moths (Prodoxus) lay their eggs on yucca species, but do not pollinate the flowers. They also do not eat the seeds, instead feeding on fruits, stems, or leaves, frequently forming gall-like structures.[55] Yucca species are the host plants for thecaterpillars of the widespread but uncommonyucca giant-skipper butterfly (Megathymus yuccae), which is found across the southern United States and northern Mexico.[56] Theursine giant skipper butterfly (Megathymus ursus), from southern Arizona, southern New Mexico, western Texas, andNuevo León, feeds on yuccas such asSchott's yucca (Yucca ×schottii) anddatil yucca (Yucca baccata), as does the more northerlyStrecker's giant skipper (Megathymus streckeri), though it prefers smaller species of yucca.[57] Thegiant skippers (Megathymini) are species that feed in the roots of yuccas and inside the leaves of agaves.[58] Beetle herbivores includeyucca weevils in the familyCurculionidae.[59] Some species ofdarkling beetle (Tenebrionidae) also feed on parts related to thestigma or the parts connecting them to the ovary as well as mating inside the flowers.[60]
In desert environments, yuccas are an important part of the ecology, improving the environment by enriching the soil with organic material and reducing erosion. The shelter the yuccas provide attracts small animals, and their waste and remains concentrate nutrients in the immediately surrounding areas, creating amicrohabitat alongside small plants.[61] Tree-like species of yucca, such as the Joshua tree, provide nesting sites for birds and materials for small rodents. Their fallen trunks provide shelter for lizards.[62] In the plains biome, species likeYucca glauca provide perches for birds as well as cover for small birds, small reptiles, and small mammals.[63] In the plains, yuccas are not a significant source of food for either native grazers or for livestock,[63] but in desert environments cattle will learn to avoid the sharp ends of the leaves and eat the base instead.[61] Similarly, goats will eat the whole head of leaves when there is no other forage available.[61] Under heavygrazing pressure grasses in the southwest are replaced by resistant native shrubs.[64]
Yucca seeds remain viable for many years in the environment due to being well protected and having plenty of energy reserves. To start germination they require a large amount of moisture.[65] Due to the scarcity of water in much of their habitat the reproduction of yuccas by seed is limited and the majority of new plants sprout from rhizomes.[66]
Yuccas are widely grown asornamental plants in gardens and landscaping.[31] Yucca plants have provided food and fibers to humans. Several yucca species have fleshy fruits that are edible, although the seeds they contain are not. Additionally, the flowers are edible both cooked and raw. The young flowering stems of some species are edible when cooked. The leaves, roots, stems, and hearts of the plants are all inedible due to high levels ofsaponins.[72]
Yucca rhizomes have been extensively used to produce soaps, shampoos, detergents and are still used to a lesser extent for this today.[73] The leaves are still used to make trays and baskets in the southwestern US.[74] Research efforts have been made into making use of the fibers as a substitute forsisal orabacá. Efforts to cultivate existing North American yucca plants for their fibers were abandoned after conclusion of the Second World War.[75] While the strength of yucca fibers is good, their harvest is uneconomical unless alternatives are unavailable.[76]
Yucca extract, specifically from the rhizomes ofMojave yucca (Yucca schidigera), is used as a foaming agent in some beverages such as root beer and soda.[77] Yucca powder is produced from yucca plants. Harvested logs are squeezed and the sap produced is then evaporated to produce the powder, which is used in food, cosmetics, pharmaceuticals, and as animal feed additives.[78] The extract is also used to reducesurface tension in water to allow it to more easily penetrate into heavy soils duringirrigation.[76]
Very soon after the start of theColumbian exchange of plants across the Atlantic Ocean, yuccas were planted in European gardens as ornamental plants with the first recorded bloom in England in 1604.[79] Though they were planted for productive uses in Mexico prior to theSpanish Conquest, it is not recorded if they used them for ornamental purposes.[80] The use of yucca as an ornamental was not well documented in the early early history of the United States, though Thomas Jefferson did growYucca filamentosa, which he called bear grass.[81]
Thespineless yucca (Yucca gigantea) is used as a common houseplant, though sometimes under the mistaken name ofYucca elephantipes.[82] When tropical yuccas are grown indoors they do not reach the large sizes they can achieve outdoors.[83]
Yuccas are widely grown as architectural plants in landscape design due to the distinctive silhouette of their leaves.[84] They are also particularly valued for their resistance to high temperatures and drought conditions.[85] They tolerate a range of conditions but are best grown in full sun in subtropical or mild temperate areas.[86] Some of the larger species of yucca are used as living barriers and fences.[73] All yuccas require good drainage, but are tolerant of difficult conditions such as dry and poor soils.[84] In cold climates when there is enough precipitation to collect in the crown of the yucca plant, thefreeze-thaw cycle can damage the plant and provide an entry for damaging fungi or bacteria.[87]
Several species of yucca can be grown outdoors intemperate climates, including:[86][88]
Harvested yucca flowers on their way toNaolinco, inVeracruz, Mexico
The flower petals are commonly eaten inCentral America and Mexico, but the plant's reproductive organs (theanthers andovaries) are first removed because of their bitterness.[89][90] Petals have a flavor reminiscent of lettuce.[91]
In addition to being calledflor de izote in Mexico, yucca flowers are also calledflores de palma (palm flowers) inHidalgo andSan Luis Potosí,guayas,cuaresmeñas, orchochos inVeracruz, andchochas inTamaulipas. In rural central Mexico, they are eaten as food, as they were in pre-Hispanic times. Bunches are sold in public markets and eaten while very fresh and tender, before they become bitter. They are also cooked with scrambled eggs or in green chili salsa in this area.[92]
Another way that yucca flowers are served is in a sauce after roasting where they are calledchochos intomachile. It is served this way as a snack or with salads in theLos Tuxtlas region of Veracruz.[93] In the northern Mexican state ofCoahuila, yucca flowers are considered a traditional food forLent.[94]
InGuatemala, they are boiled and eaten with lemon juice. InEl Salvador, the tender tips of stems are eaten and known locally ascogollo de izote.[89]
These Central American and Mexican culinary traditions have been imported to the United States to areas such as Los Angeles where the flowers of the giant yucca are eaten in season in scrambled eggs,pupusas, and tacos. Before being used as an ingredient, the petals are often blanched for five minutes, though they are also eaten raw in small amounts.[90]
In Mexico, the fleshy fruits of some yucca species are calleddatiles, the same word as for the fruit of thedate palm, though they are unrelated. These fruits are used to produce alcoholic drinks.[92] The edible fruit of thebanana yucca becomes significantly sweeter when cooked. Ifpuréed it is similar to applesauce.[95] Raw fruits have a flavor similar tostraightneck squash.[91]
Yuccas were and are one of the most important plants outside of cultivation for both ancient and contemporary native peoples in theSouthwestern US. They have a wide range of uses, from fibers to food. Some of these uses are in fishing nets, in making paintbrushes, in combs, sandals, mats, blankets, and sewing.[96] The dried and split trunks of yuccas are soft and work well for a hearth in starting fires via friction.[97] The use of items woven from yucca leaves dates from thearchaic period, 8000 to 1000BCE.[98]
The young stalks of thesoaptree yucca (Yucca elata) have been consumed by theMescalero Apache. They are roasted over an open fire and then peeled to eat the soft interior.[72] The flower stalks ofGreat Plains yucca (Yucca glauca) have been prepared similarly as recorded in the 1930s.[99] The flowers of the same species were frequently boiled to remove their bitter flavor or the flower pistil, the most bitter part, was removed.[72] The cooking of banana yucca fruits has continued to the present day among theHopi. The use of yucca shampoo for hair and to wash traditional rugs continues with theNavajo. TheJicarilla Apaches will similarly use it to clean woven baskets.[91]
The yucca flower is thestate flower ofNew Mexico in the southwestern United States. No species name is given in the law;[100] however, theSecretary of State of New Mexico website notes that thesoaptree yucca (Yucca elata) is one of the more widespread species in New Mexico.[101] It was officially designated as the state flower in 1927 by the state legislature after a survey of state students with the support of the New Mexico Federation of Women's Clubs.[101]
The yucca, specificallyYucca gigantea, is the national flower ofEl Salvador, where it is known asflor de izote.[90] It was officially designated the floral emblem in 1995.[102] Salvadorans often compare their ability to recover from periods of repression to the ability of the flor de izote to grow back after being cut.[103]
Alexander, Robert R.; Pond, Floyd W.; Rodgers, Jane E. (2008)."Yucca"(PDF). In Bonner, Franklin T.; Karrfalt, Robert P. (eds.).The Woody Plant Seed Manual. Agriculture Handbook, no. 727. Washington, D.C.: United States Department of Agriculture, Forest Service.ISBN978-0-16-081131-9.OCLC265729682.Archived(PDF) from the original on 21 April 2025. Retrieved10 May 2025.
Churchill, Steven P. (1986). "106. Apiaceae". In McGregor, Ronald L.; Barkley, T. M.; Brooks, Ralph E.; Schofield, Eileen K. (eds.).Flora of the Great Plains. Lawrence, Kansas: University Press of Kansas.ISBN978-0-7006-0295-7.OCLC13093762. Retrieved16 April 2025.
Guillot Ortiz, Daniel; Van der Meer, Piet (2009) [In Print 2008].El género Yucca L. en España [The genus Yucca L. in Spain](PDF). Monografías de la Revista Bouteloua, 2 (in Spanish) (eBook ed.). Jaca, Spain: Jolube.ISBN978-84-937291-8-9.OCLC1123383406.Archived(PDF) from the original on 22 May 2023. Retrieved18 April 2025.
Tanaka, Osamu; Tamura, Yukiyoshi; Masuda, Hitoshi; Mizutani, Kenji (1996). "Application of Saponins in Food and Cosmetics: Saponins of Mohave Yucca andSapindus mukurossi". In Waller, George R.; Yamasaki, Kazuo (eds.).Saponins Used in Food and Agriculture. Advances in experimental medicine and biology, v. 405. New York: Plenum Press.ISBN978-0-306-45394-6.OCLC35229176. Retrieved18 April 2025.
Tull, Delena (2013).Edible and Useful Plants of the Southwest : Texas, New Mexico, and Arizona: including recipes, teas and spices, natural dyes, medicinal uses, poisonous plants, fibers, basketry, and industrial uses. Austin, Texas: University of Texas Press.ISBN978-0-292-74827-9.OCLC904364435.
Webber, John Milton (1953).Yuccas of the Southwest. Agriculture monograph, no. 17. Washington, D.C.: United States Department of Agriculture.OCLC2686417. Retrieved30 April 2025.
Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; Higgins, Larry C. (1987).A Utah Flora. Great Basin Naturalist Memoirs, No. 9 (First ed.). Provo, Utah: Brigham Young University.JSTOR23377658.OCLC9986953694. Retrieved16 April 2025.
Chase, Mark W.; Reveal, James L.; Fay, Michael F. (October 2009). "A subfamilial classification for the expanded asparagalean families Amaryllidaceae, Asparagaceae and Xanthorrhoeaceae".Botanical Journal of the Linnean Society.161 (2):132–136.doi:10.1111/j.1095-8339.2009.00999.x.ISSN0024-4074.
Gray, Ihlara C.; Adolph, Stephen C. (11 June 2024). "Joshua Tree Demography and Decomposition: Implications for Desert Night Lizard Habitat".The Southwestern Naturalist.68 (2):137–146.doi:10.1894/0038-4909-68.2.137.ISSN0038-4909.
Pellmyr, Olle; Huth, Chad J. (November 1994). "Evolutionary stability of mutualism between yuccas and yucca moths".Nature.372 (6503):257–260.doi:10.1038/372257a0.
McAlpine, Kate G.; Howel, Clayson J. (2024).List of Environmental Weeds in New Zealand(PDF) (Report). Wellington, New Zealand: Department of Conservation Te Papa Atawhai.Archived(PDF) from the original on 22 February 2025. Retrieved8 May 2025.
APC (2025)."Yucca aloifolia L."Australian Plants Census (APC). Council of Heads of Australasian Herbaria (CHAH).Archived from the original on 3 May 2025. Retrieved3 May 2025.
APC (2025)."Yucca gloriosa L."Australian Plants Census (APC). Council of Heads of Australasian Herbaria (CHAH).Archived from the original on 3 May 2025. Retrieved3 May 2025.
APC (2025)." Yucca whipplei Torr".Australian Plants Census (APC). Council of Heads of Australasian Herbaria (CHAH).Archived from the original on 3 May 2025. Retrieved3 May 2025.
Castro, Leyda (1 September 2023)."Nuestra Flor Nacional es la Pieza del Mes del MUHNES" [Our National Flower is the MUHNES Article of the Month].El Museo de Historia Natural de El Salvador, Ministerio de Cultura, Gobierno de El Salvador [The Natural History Museum of El Salvador, Ministry of Culture, Government of El Salvador] (in Spanish).Archived from the original on 12 December 2024. Retrieved21 April 2025.
RAE; ASALE (2024)."izote".Diccionario de la lengua española (in Spanish). Real Academia Española, Asociación de Academias de la Lengua Española.Archived from the original on 28 December 2024. Retrieved23 November 2021.
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