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 hot and dry parts of North America, Central America, South America,
and the Caribbean.
Early reports of the species were confused with the cassava.
Consequently, Linnaeus mistakenly derived the generic name from the Taíno word for
the latter, yuca.
It is also colloquially known in the lower Midwest United States as "ghosts in the graveyard",
as it is commonly found growing in rural graveyards and when in bloom the cluster of flowers on
a thin stalk appear as floating apparitions.
Distribution
The natural distribution range of the genus Yucca covers a vast area of North and Central
America.
From Baja California in the west, northwards into the southwestern United States, through
the drier central states as far north as Alberta in Canada.
Yucca is also native to the lowlands and dry beach scrub of the Gulf and South Atlantic
states from coastal Texas to easternmost Virginia.
To the south, the genus is represented throughout Mexico and extends into Guatemala.
Yuccas have adapted to an equally vast range of climatic and ecological conditions.
They are to be found in rocky deserts and badlands, in prairies and grassland, in mountainous
regions, in light woodland, in coastal sands, and even in subtropical and semitemperate
zones, although these are generally arid to semiarid.
Ecology Yuccas have a very specialized, mutualistic
pollination system, being pollinated by yucca moths; the insect purposefully 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.
Although certain species of the Yucca moth have evolved antagonistic features against
the plant and do not assist in the plants 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, ursine
giant-skipper, and Strecker's giant-skipper.
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 stem from confusion with the similarly pronounced,
but botanically unrelated, yuca, also called cassava.
Roots of soaptree yucca 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.
In rural Appalachian areas, species such as Yucca filamentosa are referred to as "meat
hangers".
The tough, fibrous leaves with their sharp-spined tips were used to puncture meat and knotted
to form a loop with which to hang meat for salt curing or in smoke houses.
Cultivation 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.
Joshua trees are protected by law in some states.
A permit is needed for wild collection.
As a landscape plant, they can be killed by excessive water during their summer dormant
phase, so are avoided by landscape contractors.
Several species of yucca can be grown outdoors in mild temperate climates where they are
protected from frost.
These include:- Symbolism
The "yucca flower" is the state flower of New Mexico.
No species name is given in the citation.
Species As of February 2012, the World Checklist of
Selected Plant Families recognizes 49 species of Yucca and a number of hybrids:
A number of other species previously classified in Yucca are now classified in the genera
Dasylirion, Furcraea, Hesperaloe, Hesperoyucca, and Nolina.
Taxonomic arrangement Section Yucca formerly Sarcocarpa Engelm.
Series Faxonianae Hochstätter Yucca carnerosana McKelvey
Yucca faxoniana Sarg.
Series Baccatae Hochstätter Yucca baccata Torr.
Yucca baccata Torr.
ssp.
baccata Yucca baccata Torr.
ssp.
vespertina Hochstätter Yucca baccata Torr.
ssp.
thornberi Hochstätter
Yucca confinis McKelvey Yucca endlichiana Trel.
Yucca arizonica McKelvey
Series Treculianae Hochstätter Yucca grandiflora Gentry
Yucca declinata Laferr.
Yucca treculiana Carriere Yucca torreyi Shafer
Yucca schidgera Roezl ex Ortgies Yucca schotti Engelm.
Yucca capensis Lenz Yucca jaliscensis Trel.
Yucca periculosa Baker Yucca mixtecana Garcia-Mend.
Yucca decipiens Trel.
Yucca valida Brandegee Yucca potosina Rzed.
Yucca filifera Chabaud
Series Gloriosae Hochstätter Yucca gloriosa L.
Yucca recurvifolia Salisb.
Series Yucca Yucca madrensis Gentry
Yucca linearifolia Clary Yucca elephantipes Regel
Yucca lacandonica Gomez-Pompa & Valdes Yucca aloifolia L.
Yucca yucatana Engelm.
Section Clistocarpa Engelm.
Yucca brevifolia Engelm.)
Yucca brevifolia Engelm.
ssp.
brevifolia Yucca brevifolia Engelm.
ssp.
jaegeriana Hochstätter Yucca brevifolia Engelm.
ssp.
herbertii Hochstätter
Section Chaenocarpa Engelm.
Series Filamentosae Hochstätter Yucca filamentosa L.
Yucca filamentosa L. ssp.
filamentosa Yucca filamentosa L. ssp.
smalliana Hochstätter Yucca filamentosa L. ssp.
concava Hochstätter
Yucca flaccida Haw.
Series Rupicolae Hochstätter Yucca cernua Keith
Yucca pallida McKelvey Yucca queretaroensis Pina Lujan
Yucca reverchonii Trel.
Yucca rigida Trel.
Yucca rostrata Engelm.
ex Trel.
Yucca rupicola Scheele Yucca thompsoniana Trel.
Series Harrimaniae Hochstätter Yucca harrimaniae Trel.
Yucca harrimaniae Trel.
ssp.
harrimaniae Yucca harrimaniae Trel.
ssp.
neomexicana Hochstätter Yucca harrimaniae Trel.
ssp.
sterilis Hochstätter Yucca harrimaniae Trel.
ssp.
gilbertiana Hochstätter
Yucca nana Hochstätter
Series Glaucae Hochstätter Yucca angustissima Engelm.
ex Trel.
Yucca angustissima Engelm.
ex Trel.
ssp.
angustissima Yucca angustissima Engelm.
ex Trel.
ssp.
toftiae Hochstätter Yucca angustissima Engelm.
ex Trel.
ssp.
kanabensis Hochstätter Yucca angustissima Engelm.
ex Trel.
ssp.
avia Hochstätter
Yucca baileyi Wooton & Standl.
ssp.
baileyi Yucca baileyi Wooton & Standl.
ssp.
intermedia Hochstätter
Yucca coahuilensis Matuda & Pinja Lujan Yucca elata Engelm.
Yucca elata Engelm.
ssp.
elata Yucca elata Engelm.
ssp.
utahensis Hochstätter Yucca elata Engelm.
ssp.
verdiensis Hochstätter
Yucca glauca Nutt.
ssp.
glauca Yucca glauca Nutt.
ssp.
stricta Hochstätter Yucca glauca Nutt.
ssp.
albertana Hochstätter
Yucca campestris McKelvey Yucca constricta Buckley
Yucca arkansana Trel.
ssp.
arkansana Yucca arkansana Trel.
ssp.
louisianensis Hochstätter Yucca arkansana Trel.
ssp.
freemanni Hochstätter
Section Hesperoyucca Engelm.
(Treated as a separate genus Hesperoyucca by some sources.)
Yucca whipplei Torr.
ssp.
whipplei Yucca whipplei Torr.
ssp.
caespitosa Haines Yucca whipplei Torr.
ssp.
intermedia Haines Yucca whipplei Torr.
ssp.
percursa Haines Yucca whipplei Torr.
ssp.
newberryi Hochstätter Yucca whipplei Torr.
ssp.
eremica Epling & Haines
Cultivars In the years from 1897 to 1907, Carl Ludwig
Sprenger created and named 122 Yucca hybrids.
Gallery
References
General Fritz Hochstätter: Yucca.
Band 1 Dehiscent-fruited species in the Southwest and Midwest of the USA, Canada and Baja California
, Selbst Verlag, 2000.
ISBN 3-00-005946-6 Fritz Hochstätter: Yucca.
Band 2 Indehiscent-fruited species in the Southwest, Midwest and East of the USA, Selbst
Verlag. 2002.
ISBN 3-00-009008-8 Fritz Hochstätter: Yucca.
Band 3 Mexico , Selbst Verlag, 2004.
ISBN 3-00-013124-8 External links
Yucca species and their Common names - Fritz Hochstätter
UVSC Herbarium - Yucca New Mexico Statutes and Court Rules: State
Flower