yucca brevifolia

The Joshua tree is called "hunuvat chiy'a" or "humwichawa" by the indigenous Cahuilla.{{cite web |title=Joshua Tree National Park |url=http://www.nps.gov/jotr/naturescience/jtrees.htm |url-status=unfit |archive-url=https://web.archive.org/web/20150304155541/https://nps.gov/jotr/learn/nature/jtrees.htm |archive-date=2015-03-04 |access-date=2023-07-30 |work=Nature and Science: Joshua Trees |publisher=National Park Service}} It is also called izote de desierto (Spanish, "desert dagger").{{cite web |title=Yucca |url=https://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=43116 |access-date=2012-03-30 |work=Itis Report |publisher=Integrated Taxonomic Information System}} 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").{{cite web |title=Yucca brevifolia Engelm. |url=http://www.ipni.org/ipni/idPlantNameSearch.do?id=543655-1&back_page=%2Fipni%2FeditSimplePlantNameSearch.do%3Ffind_wholeName%3DYucca%2Bbrevifolia%26output_format%3Dnormal |access-date=2008-12-20 |work=International Plant Names Index |publisher=Royal Botanic Gardens, Kew}}

The name "Joshua tree" is commonly said to have been given by a group of Mormon colonists crossing the Mojave Desert in the mid-19th century. The tree's role in guiding them through the desert combined with its unique shape reminded them of a biblical story in which Joshua keeps his hands reached out for an extended period of time to enable the Israelites in their conquest of Canaan ({{bibleverse||Joshua|8:18–26|KJV}}).{{cite web |title=Joshua Tree National Park |url=http://www.nps.gov/jotr/naturescience/jtrees.htm |url-status=unfit |archive-url=https://web.archive.org/web/20150304155541/https://nps.gov/jotr/learn/nature/jtrees.htm |archive-date=2015-03-04 |access-date=2023-07-30 |work=Nature and Science: Joshua Trees |publisher=National Park Service}}{{cite web |date=2019-08-26 |title=Joshua Tree National Park |url=http://travel.nationalgeographic.com/travel/national-parks/joshua-tree-national-park/ |archive-url=https://web.archive.org/web/20100225084053/http://travel.nationalgeographic.com/travel/national-parks/joshua-tree-national-park/ |url-status=dead |archive-date=February 25, 2010 |access-date=2013-05-27 |publisher=National Geographic Society}}{{cite web |url= https://www.usanpn.org/cpp/YUBR |title= Joshua Tree (Yucca brevifolia) |work= Meet the Species: All Species |publisher= The California Phenology Project, USA National Phenology Network |access-date= 2013-05-27 }} Further, the shaggy leaves may have provided the appearance of a beard.{{cite book |last=Peattie |first=Donald Culross |url=https://books.google.com/books?id=LfH16XDaVSkC |title=A Natural History of Western Trees |publisher=Bonanza Books |others=Illustrated by Paul Landacre |year=1953 |isbn=9780395581759 |location=New York |page=304 |language=en |author-link=Donald C. Peattie}} However, no direct or contemporary attestation of this origin exists, and the name Joshua tree is not recorded until after Mormon contact;{{cite book |last=Zarki |first=Joseph |date=2015 |title=Joshua Tree National Park |url=https://books.google.com/books?id=U2NWBwAAQBAJ |location=Charleston, South Carolina |publisher=Arcadia Publishing |page=28 |isbn= 9781467132817}} moreover, the physical appearance of the Joshua tree more closely resembles a similar story told of Moses.{{cite magazine |last=Saunders |first=Charles Francis |date=1929 |title=Why Joshua Tree? |url=https://books.google.com/books?id=yRAmAQAAMAAJ |magazine=Desert |access-date=January 11, 2019 |volume=1 |page=80 |quote=An application to Mr. Frederick V. Coville, botanist of the Department of Agriculture, elicited the following response: 'The statement is often made that this name Joshua-tree was applied to Cleistoyucca brevifolia because it was this tree which led the Mormons through the desert. I have no means of knowing, however, whether this explanation is authentic or whether it was invented as an explanation of the name. It seems to me more likely that Joshua tree is a garbled Indian name' […] I asked Professor Marcus E. Jones, whose knowledge of the desert flora is unsurpassed, and who has had a long acquaintance with members of the Mormon church. In reply, he kindly wrote as follows: 'The Mormon church officials do not know exactly the origin of the term, but assume that it is from the wide-spreading arms (branches) that in the night remind of the time when in battle Joshua had his arms held up to win a battle. This I got from one of the twelve apostles of the Mormon church.' Plausible as this explanation is, its value is more or less shaken when one finds, as I did after looking up the family Bible, that it was Moses, not Joshua, who had his arms held up during the battle, while Joshua conducted the fighting (Ex. 17:8–13). There is, however, another account of a fight, which may be what the Mormon apostle had in mind. It is told in the book of Joshua 7:18–26 [sic].}}

Ranchers and miners who were contemporaneous with the Mormon immigrants used the trunks and branches as fencing and for fuel for ore-processing steam engines.{{cite web |last1=Jane |first1=Rodgers |title=Vegetation Specialist |url=https://www.nps.gov/jotr/learn/nature/jtrees.htm |website=Joshua Tree |access-date=6 October 2020}}

In addition to the autonymic subspecies Y. b. subsp. brevifolia, two other subspecies have been described:{{cite web|url=http://www.yuccaagavaceae.com/species.html |title=Yucca species |publisher=Yuccaagavaceae.com |access-date=2012-03-30}} Y. b. subsp. herbertii (Webber's yucca or Herbert Joshua tree) and Y. b. subsp. jaegeriana (the Jaeger Joshua tree or Jaeger's Joshua tree or pygmae yucca), though both are sometimes treated as varieties{{Cite book| last = Grandtner | first = Miroslav M.| year = 2005| title = Elsevier's Dictionary of Trees - North America| page = 973| url = https://books.google.com/books?id=yjc5ZYWtkNAC&q=Yucca+brevifolia&pg=PA973| isbn = 978-0-444-51784-5| publisher = Elsevier | location = Amsterdam

}}{{cite web |last=Magney |first=David L. |date=2005-09-19 |title=Checklist of Ventura County Rare Plants |url=http://www.cnpsci.org/html/PlantInfo/ChecklistofVenturaCountyRarePlants-19Sep2005.pdf |url-status=unfit |archive-url=https://web.archive.org/web/20060212160318/http://www.cnpsci.org/html/PlantInfo/ChecklistofVenturaCountyRarePlants-19Sep2005.pdf |archive-date=2006-02-12 |access-date=2023-07-30 |website=California National Plant Society, Channel Islands Chapter}} or forms.{{cite book | last = Eggli | first = Urs | year = 2001 | title = Monocotyledons | pages = 90–91, 100 | isbn = 978-3-540-41692-0 | publisher = Springer | location = Berlin }} Y.b. subsp. jaegeriana has also been treated as its own species.{{Cite journal|last=Lenz|first=Lee|date=2007-07-25|title=Reassessment of Yucca brevifolia and Recognition of Y. jaegeriana as a Distinct Species|url=https://scholarship.claremont.edu/aliso/vol24/iss1/7|journal=Aliso: A Journal of Systematic and Evolutionary Botany|volume=24|issue=1|pages=97–104|doi=10.5642/aliso.20072401.07|issn=0065-6275|doi-access=free}}{{cite iucn |author=Esque, T.C. |author2=DeFalco, L.A. |author3=Hodgson, W. |author4=Salywon, A. |author5=Puente, R. |author6=Clary, K. |date=2020 |title=Yucca jaegeriana |volume=2020 |page=e.T162386466A162386497 |doi=10.2305/IUCN.UK.2020-3.RLTS.T162386466A162386497.en |access-date=18 November 2021}}{{cite web |title=NatureServe Explorer 2.0 |url=https://explorer.natureserve.org/Taxon/ELEMENT_GLOBAL.2.156126/Yucca_jaegeriana |website=explorer.natureserve.org |access-date=31 March 2022}}

File:Joshua Tree Panicle 1.jpgs]]

Joshua trees grow quickly for a desert species; new seedlings may grow at an average rate of {{convert|7.6|cm|in|1|abbr=on}} per year in their first 10 years, then only about {{convert|3.8|cm|in|1|abbr=on}} per year.{{cite journal | last1 = Keith | first1 = Sandra L | year = 1982 | title = A tree named Joshua | journal = American Forests | volume = 88 | issue = 7| pages = 40–42 }} The trunk consists of thousands of small fibers and lacks annual growth rings, making determining the tree's age difficult. This tree has a top-heavy branch system, and a broad root system, with roots in one case found {{convert|11|m|ft|0|abbr=on}} from the nearest Joshua tree. If it survives the rigors of the desert, it can live for several hundred years. The tallest trees reach about {{convert|15|m|ft|0|abbr=on}}. 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 to 35 cm long, and 7 to 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 serrated.

Flowers typically appear from February to late April, in panicles 30 to 55 cm tall and 30 to 38 cm broad, the individual flowers erect, 4 to 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.

Once they bloom, the flowers are pollinated by the yucca moth (Tegeticula synthetica), which spreads pollen while laying eggs inside the flower. The larvae feed on the seeds, but enough seeds remain to reproduce. The Joshua tree is also able to actively abort ovaries in which too many eggs have been produced.

File:JoshuaTreeFruit 2008-06-19-25.jpg

The Joshua tree is native to the southwestern United States (Arizona, California, Nevada, and Utah) and northwestern Mexico. This range mostly coincides with the geographical reach of the Mojave Desert, where it is considered one of the major indicator species for the desert. It occurs at elevations between {{convert|400|and|1,800|m|ft|abbr=on}}.{{cite book |last=Gossard |first=Gloria Hine |title=The Joshua Tree, a Controversial, Contradictory Desert Centurion |publisher=Yellow Rose Publications |year=1992 |isbn=9780963326409}}

{{external media | width = 210px | float = right | headerimage= 210px | video1 = [https://knowablemagazine.org/article/living-world/2022/can-fire-ravaged-forest-joshua-trees-be-restored "Can a fire-ravaged forest of Joshua trees be restored?"], Tien Nguyen, Knowable Magazine, March 4, 2022.}}

Joshua trees are one of the species predicted to have their range reduced and shifted by climate change.{{Cite journal |last1=Shafer |first1=Sarah L. |last2=Bartlein |first2=Patrick J. |last3=Thompson |first3=Robert S. |year=2001 |title=Potential changes in the distributions of western North America tree and shrub taxa under future climate scenarios |journal=Ecosystems |volume=4 |issue=3 |pages=200–215 |name-list-style=amp |doi=10.1007/s10021-001-0004-5|bibcode=2001Ecosy...4..200S |citeseerx=10.1.1.569.228 |s2cid=6214861 }} Concern remains 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,{{cite journal |last1=Cole |first1=Kenneth L. |last2=Ironside |first2=Kirsten |last3=Eischeid |first3=Jon |last4=Garfin |first4=Gregg |last5=Duffy |first5=Phillip B. |last6=Toney |first6=Chris |year=2011 |title=Past and ongoing shifts in Joshua tree distribution support future modeled range contraction |url=http://www.fs.fed.us/rm/pubs_other/rmrs_2011_cole_k001.pdf |url-status=unfit |journal=Ecological Applications |volume=21 |issue=1 |pages=137–149 |doi=10.1890/09-1800.1 |pmid=21516893 |bibcode=2011EcoAp..21..137C |archive-url=https://web.archive.org/web/20111025113005/http://www.fs.fed.us/rm/pubs_other/rmrs_2011_cole_k001.pdf |archive-date=2011-10-25 |access-date=2023-07-30}}{{cite web |last=Shogren |first=Elizabeth |date=2008-02-04 |title=Outlook Bleak for Joshua Trees |url=https://www.npr.org/templates/story/story.php?storyId=17628032 |access-date=2012-03-30 |website=National Public Radio}}{{Cite news|url=https://www.theguardian.com/environment/2019/aug/10/joshua-tree-extinct-mojave-desert-climate-change|title='It makes me angry': is this the end for America's Joshua trees?|last=Singh|first=Maanvi|date=2019-08-10|work=The Guardian|access-date=2019-08-10|language=en-GB|issn=0261-3077}}{{Cite news|last=Ufberg|first=Max|date=January 20, 2022|title='Like witnessing a birth in a morgue': the volunteers working to save the Joshua trees|work=The Guardian|url=https://www.theguardian.com/environment/2022/jan/20/joshua-trees-climate-crisis-wildfires|access-date=January 20, 2022}} thus fundamentally transforming the ecosystem of the park. Wildfires, invasive grasses, and poor migration patterns for the trees' seeds are all additional factors in the species' imperilment. As an example, approximately 13%—or more than 1.3 million Joshua trees—in one of the densest Joshua tree populations in the world in Mojave National Preserve were killed in the Dome Fire in August 2020.{{Cite web |last=Olalde |first=Mark |date=2020-08-18 |orig-date=2020-08-17 |title=Dome Fire torches 43,000 acres in Mojave National Preserve, many Joshua trees burned |url=https://www.desertsun.com/story/news/2020/08/17/dome-fire-burns-in-mojave-national-park-as-temps-soar/3383180001/ |access-date=2023-07-30 |website=The Desert Sun}} Also, concern exists 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 trees' dispersal. However, ground squirrels are very effective at moving the seeds long distances.

In March 2022, California Department of Fish and Wildlife conducted a status review of the Western Joshua Tree to determine whether to list the species as threatened under the California Endangered Species Act (CESA).{{cite web |last=Bonham |first=Charlton H. |title=Report to the Fish and Game Commission Status Review of Western Joshua Tree (Yucca brevifolia) |year=2022 |publisher=California Department of Fish and Wildlife |url=https://www.biologicaldiversity.org/programs/public_lands/pdfs/Western_Joshua_Tree_Status_Review_2022-04-13.pdf |website=Center for Biological Diversity}} The study showed that the largest threat to Yucca brevifolia was wildfires, that wildfires were a threat to population density of prone areas but not to the limits of the range itself, that several population studies showed Yucca brevifolia was abundant, and that although the southern region of the species' range has been reduced, the trend is that the northern region has been expanding over the last 11,700 years as the North American ice cap melted, allowing the species to occupy its current range. The studies showing reduced population after fires used aerial photography to document populations, which would underreport smaller and thus younger trees, as was noted in the review. The review concluded:

Based on the criteria described above, the best scientific information available to the Department at this time indicates that western Joshua tree is not in danger of becoming extinct throughout all, or a significant portion, of its range due to one or more causes, including loss of habitat, change in habitat, overexploitation, predation, competition, or disease, and is not likely to become an endangered species in the foreseeable future in the absence of special protection and management efforts required by CESA.

In February 2023, California Governor Gavin Newsom's administration proposed a budget trailer bill, the Western Joshua Tree Conservation Act, to focus on protecting the climate-threatened species and permitting development in the Southern California desert. The legislation requires conservation plan for this and other species that may be threatened by climate change and would authorize the California Department of Fish and Wildlife to permit taking a western Joshua tree only under certain conditions.{{cite web |last1=Sahagun |first1=Louis |date=9 February 2023 |title=Newsom Administration offers legislation to protect western Joshua tree |url=https://www.latimes.com/environment/story/2023-02-09/newsom-offers-joshua-tree-legislation |url-access=subscription |access-date=11 February 2023 |website=Los Angeles Times}} The legislation requires a fee of up to $2500 for the removal, relocation or trimming of limbs of a Western Joshua tree, including dead trees and limbs.{{cite web |title=The Western Joshua Tree Conservation Act |url=https://trackbill.com/bill/california-assembly-bill-1008-the-western-joshua-tree-conservation-act/2369699 |website=TrackBill |date=29 June 2023 |access-date=29 June 2023}}

This bill was passed by California lawmakers in June 2023{{cite web |last1=Singh |first1=Maanvi |title=Joshua Trees win long term protection in environmental victory |url=https://www.theguardian.com/us-news/2023/jun/28/california-protect-joshua-trees-conservation |website=The Guardian |date=28 June 2023 |access-date=29 June 2023}} and went into effect on July 10, 2023.{{cite web |title=Western Joshua Tree Conservation |url=https://wildlife.ca.gov/Conservation/Environmental-Review/WJT | website=California Department of Fish and Wildlife |access-date=5 Jan 2024}}

Different forms of the species are cultivated, including smaller plants native to the eastern part of the species' range. These smaller plants grow 2.5 m tall and branch when about 1 m tall.{{cite book |url=https://books.google.com/books?id=1mIlAQAAMAAJ |title=Wild lilies, irises, and grasses: gardening with California monocots |publisher=University of California Press |year=2003 |isbn=978-0-520-23849-7 |editor-last1=Harlow |editor-first1=Nora |location=Berkeley |page=215 |language=en |editor-last2=Jakob |editor-first2=Kristin}} Red-shafted flickers make nests in the branches, which are later used by other birds.{{cite book |last=Little |first=Elbert L. |title=The Audubon Society Field Guide to North American Trees: Western Region |year=1994 |orig-year=1980 |publisher=Knopf |isbn=0394507614 |edition=Chanticleer Press|page=329}} Despite being from a desert environment they can withstand temperatures as low as -18. They have also been planted in Denver, Colorado, suggesting they may be able to tolerate occasional temperatures as cold as -23 C.{{Cite book |last1=Irish |first1=Mary |last2=Irish |first2=Mark |date=2000 |title=Agaves, Yuccas, and Related Plants : A Gardener's Guide |url=https://archive.org/details/agavesyuccasrela0000iris |url-access=registration |location=Portland, Oregon |publisher=Timber Press |page=240 |isbn=978-0-88192-442-8 |oclc=41966994 |access-date=9 May 2025}}

Before the twentieth century, Native Americans of the Mojave and western Sonoran Desert routinely used several parts of the Joshua tree as food and fiber (Cornett, J.W., 2018, Indian Uses of Desert Plants, Nature Trails Press, Palm Springs, CA). Leaf fibers were occasionally used to bind and manufacture sandals. Root sheaths were woven into baskets to add reddish-brown designs. Fruits were baked or boiled, then eaten. Seeds were ground into flour and mixed with flour from other plant species. The flour was moistened with water, and the resulting paste was kneaded into cakes and dried.

{{Reflist|33em}}

• {{cite book |last=Cornett |first=J. W. |year=2019|title=The Joshua Tree |publisher=Nature Trails Press |location=Palm Springs, California |edition=second }}

{{Wiktionary|Joshua tree}}

{{Commons and category|Yucca brevifolia}}

{{Wikispecies}}

• {{CalPhotos|Yucca|brevifolia}}
• {{Calflora|Yucca brevifolia}}
• {{PFAF|Yucca brevifolia}}
• [http://ucjeps.berkeley.edu/cgi-bin/get_JM_treatment.pl?Yucca+brevifolia Jepson Manual Treatment: Yucca brevifolia]
• [http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=220014441 eFloras.org{{snd}}Flora of North America: Yucca brevifolia]
• [http://www.efloras.org/object_page.aspx?object_id=8799&flora_id=1 eFloras.org: Range Map]
• [http://www.nps.gov/jotr/ Joshua Tree National Park website]
• [https://sand-boarding.com/desert-trees/#Joshua_Tree Desert Trees: Yucca brevifolia]

{{Taxonbar|from=Q1378081}}

{{Authority control}}

brevifolia

Category:Flora of the California desert regions

Category:North American desert flora

Category:Trees of Northern America

Category:Flora of Northwestern Mexico

Category:Natural history of the Mojave Desert

Category:Joshua Tree National Park

Category:Taxa named by George Engelmann

Category:Garden plants of North America

Category:Ornamental trees

Category:Drought-tolerant trees

Category:Joshua

Category:Succulent plants