I grew up from age 12 around these a lot on weekends because my father's favorite place to go on weekends especially after I was 20 in 1968 when he bought property on Yucca Mesa above the city of Yucca Valley. So, I climbed many of these things (but you have to be very careful if you do as they aren't as strong as regular trees and there are their thorns every where too. It's a different world around a desert landscape where you might see 50 miles in the distance with these things growing alongside cholla cactuses and barrel cactuses (the most dangerous cactus for people is the cholla (pronounced "Choya" long O short A. because Chollas little spines are sort of like small porcupine quills that once they go in you cannot pull them out easily or at all. I still have cholla quills coming out of my leg that got in there in the 1960s and 1970s when I rode my motorcycle to fast by one too close. So, stay away from cholla Cactuses and don't wear beach walkers (thongs) around them at all because their spines (quills) go right through through the foam of the soles of the sandals.
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Yucca brevifolia - Wikipedia
Plants Profile for Yucca brevifolia (Joshua tree)
Joshua Tree - Yucca brevifolia - DesertUSA
Joshua Tree Yucca brevifolia Engelm. The Joshua tree, the largest of the yuccas, grows only in the Mojave Desert. Natural stands of this picturesque, spike-leafed ...
Yucca brevifolia
From Wikipedia, the free encyclopedia
Yucca brevifolia is a plant species belonging to the genus Yucca. It is tree-like in habit, which is reflected in its common names: Joshua tree, yucca palm, tree yucca, and palm tree yucca.[2][3][4][5]Joshua tree 
In Joshua Tree National Park, California Scientific classification 
Kingdom: Plantae Clade: Angiosperms Clade: Monocots Order: Asparagales Family: Asparagaceae Subfamily: Agavoideae Genus: Yucca Species: Y. brevifolia Binomial name Yucca brevifolia
Engelm.
Natural range Synonyms[1] - Clistoyucca brevifolia (Engelm.) Rydb.
- Sarcoyucca brevifolia (Engelm.) Linding.
- Yucca arborescens (Torr.) Trel.
- Yucca jaegeriana (McKelvey) L.W.Lenz
- Yucca brevifolia subsp. jaegeriana (McKelvey) Hochstätter
- Yucca brevifolia var. jaegerana McKelvey
- Cleistoyucca arborescens (Torr.) Eastw.
- Clistoyucca arborescens (Torr.) Trel.
- Yucca arborescens (Torr.) Trel.
- Yucca brevifolia var. herbertii (J.M. Webber) Munz
- Yucca brevifolia fo. herbertii J.M. Webber
- Yucca brevifolia subsp. herbertii (J.M. Webber) Hochstätter
- Yucca brevifolia var. jaegerana McKelvey
- Yucca draconis var. arborescens Torr.
This monocotyledonous tree is native to the arid southwestern United States, specifically California, Arizona, Utah, and Nevada, where it is confined mostly to the Mojave Desert between 400 and 1,800 m (1,300 and 5,900 ft) elevation. It thrives in the open grasslands of Queen Valley and Lost Horse Valley in Joshua Tree National Park. A dense Joshua tree forest also exists in Mojave National Preserve, in the Cima Dome, (Cima, California), northeast of Kingman, Arizona in Mohave County, Arizona, as well as along U.S. 93 between the towns of Wickenburg and Wikieup, and designated as the Joshua Tree Parkway of Arizona.
Contents
Taxonomy
The name Joshua tree was given by a group of Mormon settlers crossing the Mojave Desert in the mid-19th century. The tree's unique shape reminded them of a Biblical story in which Joshua reaches his hands up to the sky in prayer.[6][7][8] Ranchers and miners who were contemporary with the Mormon immigrants used the trunks and branches as fencing and for fuel for ore-processing steam engines. It is also called izote de desierto (Spanish, "desert dagger").[9] It was first formally described in the botanical literature as Yucca brevifolia by George Engelmann in 1871 as part of the Geological Exploration of the 100th meridian or Wheeler Survey.[10]
In addition to the autonymic subspecies Yucca brevifolia subsp. brevifolia, two other subspecies have been described:[11] Yucca brevifolia subsp. jaegeriana (the Jaeger Joshua tree or Jaeger's Joshua tree or pygmae yucca) and Yucca brevifolia subsp. herbertii (Webber's yucca or Herbert Joshua tree), though both are sometimes treated as varieties[9][12][13] or forms.[14]
Growth and development
Joshua trees are fast growers for the desert; new seedlings may grow at an average rate of 7.6 cm (3.0 in) per year in their first ten years, then only about 3.8 cm (1.5 in) per year.[15] The trunk consists of thousands of small fibers and lacks annual growth rings, making it difficult to determine the tree's age. This tree has a top-heavy branch system, but also what has been described as a "deep and extensive" root system, with roots reaching up to 11 m (36 ft).[2] If it survives the rigors of the desert, it can live for hundreds of years; some specimens survive a thousand years. The tallest trees reach about 15 m (49 ft). New plants can grow from seed, but in some populations, new stems grow from underground rhizomes that spread out around the parent tree.
The evergreen leaves are dark green, linear, bayonet-shaped, 15–35 cm long and 7–15 mm broad at the base, tapering to a sharp point; they are borne in a dense spiral arrangement at the apex of the stems. The leaf margins are white and serrate.
Flowers appear from February to late April, in panicles 30–55 cm tall and 30–38 cm broad, the individual flowers erect, 4–7 cm tall, with six creamy white to green tepals. The tepals are lanceolate and are fused to the middle. The fused pistils are 3 cm tall and the stigma cavity is surrounded by lobes. The semi-fleshy fruit that is produced is green-brown, elliptical, and contains many flat seeds. Joshua trees usually do not branch until after they bloom (though branching may also occur if the growing tip is destroyed by the yucca-boring weevil), and they do not bloom every year. Like most desert plants, their blooming depends on rainfall at the proper time. They also need a winter freeze before they bloom.Flowers grow in panicles
Once they bloom, the trees are pollinated by the yucca moth, which spreads pollen while laying her eggs inside the flower. The moth larvae feed on the seeds of the tree, but enough seeds are left behind to produce more trees. The Joshua tree is also able to actively abort ovaries in which too many eggs have been laid.
Distribution and habitat
Yucca brevifolia is endemic to the Southwestern United States with populations in western Arizona, southeastern California, southern Nevada, and southwestern Utah. This range mostly coincides with the geographical reach of the Mojave Desert,[2] where it is considered one of the major indicator species for the desert. It occurs at altitudes between 400 and 1,800 m (1,300 and 5,900 ft).[16]
Conservation status
In a 2001 paper published in the journal Ecosystems, Joshua trees are one of the species predicted to have their range reduced and shifted by climate change.[17] There is concern that they will be eliminated from Joshua Tree National Park, with ecological research suggesting a high probability that their populations will be reduced by 90% of their current range by the end of the 21st century,[18][19] thus fundamentally transforming the ecosystem of the park. There is also concern about the ability of the species to migrate to favorable climates due to the extinction of the giant Shasta ground sloth (Nothrotheriops shastensis) 13,000 years ago; ground sloth dung has been found to contain Joshua tree leaves, fruits, and seeds, suggesting that the sloths might have been key to the tree's dispersal.[18][19]
Uses and cultivation
Different forms of the species are cultivated, including smaller plants native from the eastern part of the species range. These smaller plants grow 2.5 meters tall and branch when about a meter tall.[20]Fruit
Cahuilla Native Americans, who have lived in the southwestern United States for generations, identify this plant as a valuable resource and call it "hunuvat chiy’a" or "humwichawa". Their ancestors used the leaves of Y. brevifolia to weave sandals and baskets, in addition to harvesting the seeds and flower buds for meals.
Yucca tree roots have saponin glycosides.[21]
See also
References
- "Yucca brevifolia". Tropicos.
- Burdock, George A. (2005). Fenaroli's handbook of flavor ingredients. Boca Raton, Fla.: CRC Press. p. 1913. ISBN 0-8493-3034-3.
Further reading
- Cornett, J. W. (1999). The Joshua Tree. Palm Springs, California: Natural Trails Press.
External links
Categories:
- Yucca
- Flora of the California desert regions
- North American desert flora
- Trees of the Southwestern United States
- Endemic flora of the United States
- Natural history of the Mojave Desert
- Joshua Tree National Park
- Taxa named by George Engelmann
- Garden plants of North America
- Ornamental trees
- Drought-tolerant trees
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