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Ageratina occidentalis
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Western Snakeroot
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Ageratina occidentalis

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About Western Snakeroot (Ageratina occidentalis) Ageratina occidentalis is a species of flowering plant in the daisy family known by the common name western snakeroot. It is native to the western United States where it grows in several types of habitat. This is a rhizomatous perennial herb growing fuzzy green or purple stems to a maximum height near 70 centimeters. The hairy leaves are triangular in shape with serrated edges. The flower cluster is a dense cluster of fuzzy flower heads containing long, protruding disc florets in shades of white, pink, and blue. There are no ray florets. The fruit is an achene a few millimeters long with a rough, bristly pappus.
Plant Description
Plant Type
Perennial herb

Max. Height
2.3 ft (0.7 m)

Flower Color

Native Status

Natural Setting
Site Type
Rocky places

Part Shade

Elevation ?
66' - 14019'

Annual Precip. ?
5.5" - 130.9"

Summer Precip. ?
0.36" - 4.39"

Coldest Month ?
9.1° F - 53.9° F

Hottest Month ?
32.8° F - 79.8° F

Humidity ?
0.28 vpd - 31.58 vpd

Sunset Zones ?
2*, 7*, 8, 9, 10, 11, 14, 15, 16, 17, 18, 19, 20, 21

Landscaping Information
Nursery Availability
Rarely Available

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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