Cephalanthus occidentalis Shrubland Alliance
Button willow thickets
Button willow thickets
USDA Ecological Section Map
Summary Information
- Primary Life FormShrub
- Elevation5-1000 m
- State RarityS2
- Global RarityG5
- DistributionUSA: AL, CA, DE, GA, IL, IN, KY, MA, MD, MO, MS, RI, TN, VA (NatureServe)
- Endemic to CaliforniaNo
- Endemic to California Floristic Province and DesertsNo
- Date Added1995/11/01
Characteristic Species
Cephalanthus occidentalis is dominant in the shrub or small tree canopy with Cornus sericea, Salix exigua, Salix gooddingii and Salix lucida ssp. lasiandra.
Vegetation Layers
Shrubs < 6 m; canopy is continuous, intermittent, or open. Herbaceous layer is sparse or grassy.
Membership Rules
Habitats
Seasonally flooded basins, sloughs, oxbow basins on floodplains with subsurface water at the end of the growing season. Soils are poorly aerated and fine textured. The USFWS Wetland Inventory (1996 national list) recognizes Cephalanthus occidentalis as an OBL plant.
Other Habitat, Alliance and Community Groupings
| MCV (1995) | Buttonbush series |
| NVCS (2009) | Cephalanthus occidentalis seasonally flooded shrubland alliance |
| Calveg | Willow (riparian scrub) |
| Holland | Buttonbush scrub |
| Munz | Not treated |
| WHR | Valley foothill riparian |
| CDFW CA Code | 63.300.00 |
National Vegetation Classification Hierarchy
| Formation Class | Mesomorphic Tree Vegetation (Forest and Woodland) |
| Formation Subclass | Temperate Forest |
| Formation | Temperate Flooded and Swamp Forest |
| Division | Western North America Warm Temperate Flooded and Swamp Forest |
| Macro Group | Southwestern North American Riparian, Flooded and Swamp Forest |
| Group | Southwestern North American riparian/wash scrub |
Remarks
Cephalanthus occidentalis is a wetland shrub common to many swamps and floodplains of southeastern North America as well as marshes, ditches, and other riparian areas in California. This tall, deciduous shrub or small tree can reach 6 m in height. Small, white flowers occur in dense, spherical clusters at the ends of the branches. Fruits are brown nutlets that form round clusters called buttons. Plants regenerate by seed, but the germination rate is low; plants sprout from root crowns (Snyder 1991b).
Stands of C. occidentalis are localized in California. Stands are typically dense along slow-moving or still waterways, such as oxbow lakes, sloughs, and levees with high water tables along riparian corridors (Holland 1986, Vaghti and Greco 2007).
Stands of C. occidentalis are localized in California. Stands are typically dense along slow-moving or still waterways, such as oxbow lakes, sloughs, and levees with high water tables along riparian corridors (Holland 1986, Vaghti and Greco 2007).
Life History Traits of the Principal Species
| Cephalanthus occidentalis | |
|---|---|
| Life forms | Tree, shrub; winter deciduous |
| Seed storage | None |
| Seed longevity | Short |
| Mode of dispersal | Animal; wind |
| Germination agents | Inundation (moisture dependent) |
| Mode of sprouting | Underground structures |
| Survivability after fire/disturbance | Fire-hardy(?); high sprouter |
| Disturbance-stimulated flowering | No |
| Reproductive range | Life of plant |
| Recruitment | Low |
| Regional variation | Low |
Fire Characteristics
Fluvial processes rather than fire primarily disturb stands. Plants can sprout after fires.
| Fire return interval | — |
| Seasonality | — |
| Size/extent | — |
| Complexity | — |
| Intensity | — |
| Severity | — |
| Type | — |
| Regional knowledge | — |
Regional Status
The range of Cephalanthus occidentalis includes the Central California Coastal Ranges (M262A).
- Great Valley (262A). Many small stands occur in riparian settings throughout most of the section. Stands in the Sacramento-San Joaquin River delta (Hickson and Keeler-Wolf 2007) form narrow strips along levees. They create a fine scale mosaic with other riparian alliances as the Cosumnes River Preserve near Sacramento (Vaghti and Greco 2007).
- Klamath Mountains (M261A). Small stands are local along Trinity River near Big Flat, along Hayfork Creek, and along creeks in the Redding area.
- Northern California Coast Ranges (M261B). Stands conspicuously border the northern shore of Clear Lake.
- Northern California Interior Coast Ranges (M261C). Stands occur along many of the major creeks and streams crossing the section.
- Sierra Nevada (M261E). Stands occur along Merced River below Yosemite National Park and in the Piute and Tehachapi Mountains (Twisselmann 1967).
- Sierra Nevada Foothills (M261F). Stands along several of the major rivers are short in stature because of regular damage from spring flooding. Stands along smaller riparian corridors occur on mixed and sandy alluvium (Klein et al. 2007)
Management Considerations
Levees and land alteration for agriculture have destroyed most stands in the San Joaquin Valley and elsewhere (Vaghti and Greco 2007). The record tree grows just north of the town of Buttonwillow, surrounded by cotton fields.
Associations
- Cephalanthus occidentalis [1], [2], [3]
References
- [1] Klein, A.;Crawford, J.;Evens, J.;Keeler-Wolf, T.;Hickson, D. 2007
- [2] Buck-Diaz, J.;Batiuk, S.;Evens, J.M. 2012
- [3] Ratchford, J.;Harbert, B;Boul, R.;Keeler-Wolf, T.;Evens, J. 2024a
- Barry, W.J. 1989a
- Barry, W.J. 1989b
- Cheatham, N.H.;Haller, J.R. 1975
- Holland, R.F. 1986
- Holstein, G. 1984
- Snyder, S.A. 1991b
- Thorne, R.F. 1976