YUCCA: CHARACTERISTICS, HABITAT, USES, CARE, SPECIES - BIOLOGY - 2025

Yucca is a genus of species of succulent and perennial, shrub or arboreal plants, belonging to the Asparagaceae family of the Asparagales order. It comprises about 40-50 species with hardy evergreen rosette-growing leaves with large terminal panicles of whitish flowers.

Most species are acaules or stemless, with a rosette of firm, lanceolate leaves at the base. Others are large species with a single or branched stem, with the rosette of rigid or flexible leaves in the terminal position of the stem.

The Joshua tree (Yucca brevifolia). Source: pixabay.com

The flowers are generally campanulate, light in color and very showy, and are grouped in panicles in the upper part of the plant. These species are native to the hot and dry regions of southeastern North America, Mesoamerica, and the Caribbean.

Of the Yucca genus, the Yucca brevifolia (Joshua tree) stands out with more than 10 m in height. The species Yucca aloifolia (Spanish bayonet), Yucca gloriosa (Spanish dagger) and Yucca filamentosa (Adam's needle) are widely cultivated as ornamentals for their characteristic appearance and attractive flowering.

General characteristics

Morphology

The species of the genus Yucca are generally arborescent, arboreal, herbaceous or woody plants with apical growth in the form of a rosette. The lanceolate leaves are grouped in the terminal part of the stem and branches. They are generally flat or concave, firm or wavy.

The margins of the leaves are smooth, filamentous or slightly serrated, and the apex of each leaf regularly ends in a thick, stiff spine. The inflorescence appears as a long, erect or hanging panicle with abundant globose or campanulate hermaphroditic flowers of light tones.

The fruit is a succulent fleshy indehiscent capsule, or a hard, dry dehiscent capsule. The small compressed seeds are dark in color.

Paniculate Yucca inflorescences. Source: pixabay.com

Taxonomy

- Kingdom: Plantae.

- Division: Angiospermae.

- Class: Monocotyledoneae.

- Order: Asparagales.

- Family: Asparagaceae.

- Subfamily: Agavoideae.

- Genus: Yucca L.

Synonymy

- Codonocrinum Willd. ex Schult. & Schult.f. in JJRoemer & JASchultes.

- Clistoyucca (Engelm.) Trel.

- Samuela Trel.

- Sarcoyucca (Trel.) Linding.

Adaptation

Most Yucca species have thick, waxy cuticles to prevent water loss through evapotranspiration. In fact, they store water in their thick, fleshy leaves, and some species have roots that specialize in storing liquids.

In xerophilic environments, certain species of Yucca have an oily coating on the surface of the leaves, which favors the retention of humidity. In fact, in times of drought the plants drop the leaves to reduce the loss of moisture by perspiration.

The ribbed leaves of some species direct dew and precipitation toward the roots. Likewise, the dry leaves accumulated around the trunk protect the plant from high solar radiation.

Most Yucca plants are highly adaptable to fire, as they grow and develop vigorously after forest fires.

Habitat and distribution

These species show great adaptability to a wide range of ecological and climatic conditions in tropical and semi-temperate zones, generally arid or semi-arid. In fact, they are found in rocky deserts, wastelands, grasslands, grasslands, mountains, low-lying forests, and coastal shorelines.

Its natural distribution range is located throughout the tropical areas of the American continent. In Mexico and Guatemala, the species Yucca guatemalensis is common, which is also distributed throughout Baja California towards the southwestern United States.

Some species are adapted to the climatic conditions of the central states to Alberta, Canada, where the species Yucca glauca ssp. Albertana. In addition, they are prevalent in coastal areas in the southeastern US, from Texas to Maryland, and along the Gulf of Mexico.

Several species and varieties are native to the Caribbean Islands, being common in the coastal lowlands and xerophilous scrub near the coasts. The Yucca filamentosa species is common in coastal sands.

Species of the genus Yucca are common in xerophilous environments. Source: pixabay.com

Applications

The rustic appearance and easy handling of most of the species favors their use as ornamental plants. Likewise, stems, flowers, fruits and seeds of some species are used to prepare various dishes of artisan cuisine.

The roots of the Yucca elata have a high content of saponins, which is why they are used in a traditional way for the production of soaps by the Native Americans. Some species contain steroids used in the pharmaceutical industry.

The dry leaves and the fibers of the trunk are used to obtain charcoal. The fibers of the leaves are used to make bows, ropes, sacks, baskets and handmade rugs.

As a medicinal plant, Yucca species are used externally to relieve pain and wounds. In potions and decoctions they help prevent discomforts caused by rheumatoid arthritis, colitis, allergies, some types of cancer, and improve blood circulation.

Care

Plants of the genus Yucca reproduce by seeds, suckers, or stem and root cuttings. They are very rustic plants that tolerate sandy and dry soils with little or no irrigation, as well as sudden changes in temperature.

They grow and develop in full sun exposure or partially shaded places. Most are plants widely used in gardening, being ideal for gardens, patios or parks due to their low maintenance.

At the time of sowing, enough space must be provided around to avoid competition with other species as they grow and increase in size.

Representative species

Yucca aloifolia L.

Species native to Mexico and the southern United States characterized by its unique or branched woody trunk that is 5-6 m high. The firm, lanceolate leaves are 25-40 cm long by 4-6 cm wide, with serrated margins and a sharp end.

Yucca aloifolia. Source: Stan Shebs

The erect panicle 30-50 cm long develops at the apex of the stem. It has campanulate flowers 6 cm long, white with reddish spots. In some varieties, the leaves have parallel bands of yellowish-white tones.

Yucca brevifolia Engelm.

Arborescent and branched species native to North America, differentiated by the rosette arrangement of its rigid and lanceolate leaves. The 15-60 cm long by 1-2 cm wide leaves have jagged margins and a very sharp tip.

Yucca brevifolia. Source: Stan Shebs

The firm panicle 35-40 cm in length originate from the leaves. The 3-5 cm long flowers with greenish-yellow tones generate an indehiscent ovoid fruit of 5-10 cm.

Yucca elata Engelm.

Large perennial species native to North America (Arizona, New Mexico and Texas) and northern Mexico (Coahuila, Chihuahua and Sonora). The plant has a 3-5 m high branched woody stem with flat, flexible, 40-70 cm leaves with filamentous margins and pale green tones.

Yucca elata. Source: Stan Shebs

The long panicle forms on the leaves showing abundant 3-5 cm flowers of light cream tones and pink spots. The fruit is a dehiscent capsule with numerous winged seeds.

Yucca filamentosa L.

Acaulean species native to the south and east coast of the United States. It is a low-growing plant that barely reaches one meter in length, it develops in a rosette with abundant basal shoots.

Yucca filamentosa. Source: Jerzy Opioła

The thin and ductile leaves, 50 cm long by 3 cm wide, have a blue-green hue. The paniculate inflorescence has hanging flowers of 5 cm of cream-white tone and pink spots.

Yucca filifera Chabaud

Arborescent species native to Mexico, which is distributed in the states of Coahuila, Guanajuato, Hidalgo, Mexico, Michoacán, Nuevo León, Querétaro, San Luis Potosí, Tamaulipas and Zacatecas. The rough and branched bark plant reaches 10 m in height.

Yucca filifera. Source: Rebou

The lanceolate leaves, 50-55 cm long by 3-4 cm wide, are narrow at the base and have slightly filamentous margins. The trunk is crowned with a hanging panicle of 1-2 m and abundant flowers of 5-7 cm of cream-white tones.

Yucca gloriosa L.

Shrubby species with a 2-3 m tall woody stem native to the southeastern US, from North Carolina to Florida. Known as Peruvian chamagra, Spanish dagger, Cuban hawthorn, pita or shiny yucca, it is a perennial branched from the base used in gardening.

Glorious Yucca. Source: KENPEI

The flexible leaves 30-60 cm long by 4-5 cm wide have smooth margins and are deep green in color. The panicle originates between the leaves, and has small bell-shaped flowers of creamy-white, greenish or reddish tones.

Yucca recurvifolia Salisb.

A shrubby species of medium size (2-3 m tall) characterized by its curved stem, native to the southeastern US The blue-green leaves are flexible and curved. In addition, the margins have a yellow border.

Yucca recurvifolia. Source: Stan Shebs

In the cultivar "Variegata" the midrib is yellow. Terminally, it has a broad panicle 1-2 m long with large (7-8 cm) cream-colored flowers.

Yucca rupicola Scheele

It is a short acaule species (25-75 cm tall) native to Texas and northeast Mexico (Coahuila, Nuevo León). The plant is made up of a group of rosettes or an individual one, with 20-60 cm wavy leaves, slightly serrated edges and a red-orange stripe.

Yucca rupicola. Source: Stan Shebs

Each leaf has a firm terminal spine of brown color and 5 mm in length. The 2 m high inflorescence has numerous hanging campanulate flowers of a greenish-white color.

Yucca schottii Engelm.

Large species (5-6 m tall) native to southeastern Arizona, southwestern New Mexico and the states of Sonora and Chihuahua in Mexico. Called Schott's yucca, canosa yucca or Yucca mountain yucca, it has a single stem that is sometimes branched in the terminal part.

Yucca schottii. Source: M. Bechtold

The 50-100 cm long leaves are smooth, grayish-green, concave, slightly wavy and terminated by a brown thorn. The 1 m high paniculate inflorescence presents globose white flowers.

Yucca treculeana Carrière

A branching arborescent species on the upper two-thirds native to Mexico (Coahuila) and the southern US (New Mexico, Texas). Known as Spanish bayonet, Spanish dagger or Don Quixote lace, it is a plant that reaches 5-8 m in height.

Yucca treculeana. Source: Rebou

The 80-120 cm leaves develop in a rosette at the end of the stems. They are erect, slightly concave and with a terminal black spine. The inflorescence appears as a 1 m long panicle on the leaves, with abundant globose flowers of light cream color.

References

1. Magallán-Hernández, F., Maruri-Aguilar, B., Sánchez-Martínez, E., Hernández-Sandoval, L., Luna-Zúñiga, J., & Robledo-Mejía, M. (2014). Taxonomic considerations of Yucca queretaroensis Piña (Agavaceae), an endemic species of the Queretano-Hidalguense semi-desert. Acta botánica mexicana, (108), 51-66.
2. Ortiz, DG, & Van der Meer, P. (2009). The genus Yucca L. in Spain (Vol. 2). José Luis Benito Alonso. Bouteloua Magazine, Nº 2, 124 pp. ISBN ebook: 978-84-937291-8-9.
3. Sánchez de Lorenzo-Cáceres, JM (2003) Yucca genus plants grown in Spain. Recovered in: arbolesornamentales.es
4. Wikipedia contributors. (2019). Yucca. In Wikipedia, The Free Encyclopedia. Recovered at: en.wikipedia.org
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6. Yucca. (2019). Wikipedia, The Free Encyclopedia. Recovered at: es.wikipedia.org