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San Joaquin Spearscale
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Extriplex joaquinana

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About San Joaquin Spearscale (Extriplex joaquinana) Extriplex joaquinana is a species known by the common name San Joaquin saltbush. It was formerly included in genus Atriplex. It is endemic to California, where it grows in alkaline soils in the Sacramento-San Joaquin River Delta and adjacent parts of the Central Valley and eastern Central Coast Ranges. This is an annual herb growing erect to a maximum height near one meter. The leaves are 1 to 7 centimeters in length, often scaly, green to gray-green in color, and oval to triangular in shape. The leaves are mostly located lower on the erect plant; those further up the stem are reduced in size. The inflorescences of male flowers are dense, heavy spikes, and the female flowers are held in smaller clusters. Systematics. The first publication of this taxon was in 1904 by Aven Nelson as Atriplex joaquinana A. Nelson (in: Proceedings of the Biological Society of Washington 17(12): 99). (It has sometimes been wrongly spelled Atriplex joaquiniana). In 2010, after phylogenetic research, Elizabeth H. Zacharias classified it in a new genus Extriplex, as Extriplex joaquinana (A. Nelson) E. H. Zacharias. Extriplex joaquinana belongs to the tribe Atripliceae in the Chenopodioideae subfamily of Amaranthaceae.
Plant Description
Plant Type
Annual herb

Max. Height
0.33 - 3.3 ft (0.1 - 1 m)

Native Status
Natural Setting
Elevation ?
512' - 2231'

Annual Precip. ?
15.3" - 32.2"

Summer Precip. ?
0.23" - 0.48"

Coldest Month ?
44.0° F - 48.1° F

Hottest Month ?
70.8° F - 73.4° F

Humidity ?
1.05 vpd - 22.39 vpd

Landscaping Information
Nursery Availability
Never or Almost Never Available

Other Names
Common Names
San Joaquin Saltbush

Sources include: Wikipedia. All text shown in the "About" section of these pages is available under the Creative Commons Attribution-ShareAlike License. Plant observation data provided by the participants of the California Consortia of Herbaria, Sunset information provided by Jepson Flora Project. Propogation from seed information provided by the Santa Barbara Botanical Garden from "Seed Propagation of Native California Plants" by Dara E. Emery. Sources of plant photos include CalPhotos, Wikimedia Commons, and independent plant photographers who have agreed to share their images with Calscape. Other general sources of information include Calflora, CNPS Manual of Vegetation Online, Jepson Flora Project, Las Pilitas, Theodore Payne, Tree of Life, The Xerces Society, and information provided by CNPS volunteer editors, with special thanks to Don Rideout. Climate data used in creation of plant range maps is from PRISM Climate Group, Oregon State University, using 30 year (1981-2010) annual "normals" at an 800 meter spatial resolution.

Links:   Jepson eFlora Taxon Page  CalPhotos  Wikipedia  Calflora

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