Species Brief
Fremontodendron californicum, California flannelbush
Written
August, 2026
Contributors
Ilana L. Abrahamson - 1st Compiler, Leila Duchac - 1st Editor
Abrahamson, Ilana L., compiler. 2026. Species Brief: Fremontodendron californicum, California flannelbush. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory (Producer). Available: https://research.fs.usda.gov/feis/species-briefs/frecal
DOI
10.2737/feis-species-brief-frecal
Scientific Name
Fremontodendron californicum
Common Names
California flannelbush
fremontia
Slippery elm
California slippery-elm
California fremontia
flannelbush
FEIS Lifeform Type
Shrub
Tree
Kingdom
Plantae
Class
Magnoliopsida (Dicot)
Order
Malvales
Family
Sterculiaceae
Genus
Fremontodendron
Nativity
Native
Invasiveness
Noninvasive
This Species Brief is a concise summary of the biological, ecological, and fire‑related characteristics of an individual species derived from a Fire Effects Information System (FEIS) Species Review. Table 1 is derived from a standardized template and highlights these characteristics.
| Attribute | Characteristic | Justification | Source |
|---|---|---|---|
| Biological characteristics | |||
| Life form | Shrub; Tree | California flannelbush is a loosely branched, erect shrub or small tree growing about 1.5 to 5 m tall and branching near the ground. | FEIS: Botanical Description [1] |
| Typical lifespan | Insufficient information | The source does not provide explicit information about typical lifespan of individual plants. | FEIS [1] |
| Life cycle | Perennial | An evergreen, woody perennial; leaves generally persist about 2 years. | FEIS: Botanical Description; Successional Status [1] |
| Drought tolerance | High | California flannelbush is most common on dry sites in mountainous areas with a mediterranean climate of hot, dry summers and cool, wet winters. It can dominate desert and semi-desert chaparral. | FEIS: Site Characteristics; Plant Communities [1] |
| Rooting depth | Shallow* | Little information is available about California flannelbush roots. One source describes "running roots" with sprouts up to 1.5 m from the parent plant. Another source describes shallow, wide-spreading roots in a horticultural hybrid. | FEIS: Botanical Description [1] |
| Bark thickness at maturity | Insufficient information | The bark is described as rough, deeply fissured, and scaly with mucilaginous inner bark, but bark thickness is not given. | FEIS: Botanical Description [1] |
| Sheds low branches | Rarely/No | California flannelbush often grows as a shrub with branches near the ground, and these low branches are noted as fuel that may carry surface or crown fires. | FEIS: Botanical Description; Fuel Characteristics [1] |
| Reproduction and Regeneration | |||
| Adventitious buds | Root sprouts; Root crown* | California flannelbush spreads vegetatively via root sprouts, and it sprouts after top-kill from fire, browsing, or mechanical damage. Sprouts originate from roots and from the stem base, presumably the root crown. | FEIS: Vegetative Regeneration |
| Time to reproductive maturity | 2-5 years | California flannelbush plants may reach sexual maturity in their second growing season, and seeds may be produced on plants as young as 2 years old. | FEIS: Seed Production and Mortality; Summary [1] |
| Soil seed bank longevity | Long-term persistent (>5 years)* | Direct observations of a long-term soil seed bank come from a related species: over 80% of Pine Hill flannelbush seeds remained viable after 5.75 years buried under litter. The same is inferred and often stated for California flannelbush, given similar scarification needs and heat-stimulated germination. | FEIS: Germination and Seed Banking [1] |
| Serotinous cones | N/A | This attribute applies to conifers. California flannelbush has bristly, 5-valved capsules, and seeds are retained in the capsules only about a month after ripening. | FEIS: Botanical Description; Seasonal Development [1] |
| Seed dispersal mechanism | Animal; Gravity | Seeds first fall from the capsules and are then dispersed by ants, which are attracted to the seeds' fatty eleiosomes and carry them without harming the seed. | FEIS: Seed Dispersal [1] |
| Seed dispersal distance | Short (mostly under parent plant) | Seeds are likely dispersed by ants over short distances; in the related Pine Hill flannelbush, seeds on ant middens were mostly within 8 m of parent plants, with the farthest at 12 m. | FEIS: Seed Dispersal; Introductory summary [1] |
| Optimal conditions for seedling establishment | Bare soil; Sun | Establishment is restricted to the early postfire environment, which typically has exposed mineral soil and abundant sunlight. | FEIS: Seedling Establishment and Plant Growth [1] |
| Successional Status | |||
| Shade tolerance | Moderately shade tolerant* | One author notes that California flannelbush appears capable of enduring considerable shade but is rarely subjected to it shade. It occurs in the understory of pinyon-juniper woodlands, but it is most abundant during the first 80 years after fire. Seedling establishment is restricted to the early postfire environment with exposed mineral soil and abundant sunlight. | FEIS: Successional Status; Seedling Establishment and Plant Growth [1] |
| Successional status | Early; Mid; Late* | California flannelbush is typically most abundant in early postfire environments in both chaparral and pinyon-juniper woodlands. It persists into late-successional chaparral (about 100 years) but is rarely seen in late succession in singleleaf pinyon woodlands, so late-stage persistence occurs in chaparral but not in pinyon woodlands. | FEIS: Summary; Successional Status [1] |
| Fire | |||
| Primary fire response(s) or adaptation(s) | Recover/Resprout; Recruit | California flannelbush is well-adapted to fire because fire stimulates sprouting and because seedling recruitment is largely restricted to the early postfire environment, where it establishes from a fire-scarified, persistent soil seed bank. It is classified as a "fire-recruiter" and "facultative seeder". | FEIS: Fire Adaptations [1] |
| Germination is fire stimulated | Often | High temperatures stimulate germination. Observations of postfire seedling establishment and heat treatment experiments suggest that fire scarifies California flannelbush seed and stimulates germination. | FEIS: Germination and Seed Banking; Immediate Fire Effects [1] |
| Flowering/fruiting is fire stimulated | Often* | While details are lacking, the source states that fire stimulates seed production. | FEIS: Immediate Fire Effects [1] |
| Season when it is most sensitive to fire | Insufficient Information | Specific information comparing fire effects on California flannelbush in different seasons was not available. However, in California chaparral communities where California flannelbush occurs, spring fires may burn with lower intensity than summer or fall fires, but they may be more likely to harm underground structures and the soil seed bank. | FEIS: Fire Regimes [1] |
| Plant flammability | High* | As an evergreen shrub or small tree with low branches, it may carry surface or crown fires, especially when it forms dense thickets. The dry-mesic chaparral it occurs in forms highly flammable, stand-replacing stands; flammability is described mainly at the stand scale rather than measured for the species alone. | FEIS: Fuel Characteristics [1] |
| Early colonizer/recolonizer of burned or disturbed sites | Frequently | California flannelbush is typically most abundant in early postfire environments in both chaparral and pinyon-juniper woodlands. It may establish local thickets in early postfire succession. | FEIS: Summary; Plant Response to Fire [1] |
| Effect of fire exclusion on population | Possible decrease | California flannelbush can persist into late succession (about 100 years) in California chaparral, but where chaparral succeeds to woodlands after long fire-free intervals its abundance declines. Given that California flannelbush is typically most abundant in early postfire environments, populations may decrease with fire exclusion. | FEIS: Fire Management Considerations [1] |
| Is this species typically managed with prescribed fire? | Insufficient information | No information is available on current fire management specific to California flannelbush. However, in fall or winter, tribes in the Sierra Nevada burned individual shrubs or sites where the shrubs grew to induce rapid growth. | FEIS: Fire Management Considerations; Other Uses [1] |
| Predominant historical fire frequencies of ecosystem where it most commonly occurs | Mid-frequency | Historical mean fire intervals in the chaparral communities where California flannelbush most commonly occurs were about 55 years for California chaparral and 65 years for semi-desert chaparral, with ranges of roughly 35 to 115 years. | FEIS: Fire Regimes [1] |
| Predominant historical fire severity where it most commonly occurs | Replacement | The California chaparral where California flannelbush most commonly occurs is characterized by intense, stand-replacing crown fires. Landfire models describe the dry-mesic, semi-desert, and xeric serpentine chaparral biophysical setting series as having 100% replacement-severity fire. | FEIS: Summary; Fire Regimes; 2020 LANDFIRE Biophysical Settings [1] |
| Predominant historical fire regime group where it most commonly occurs | 4 | Dry-mesic, semi-desert, and xeric serpentine chaparral biophysical settings where California flannelbush most commonly occurs are assigned to Fire Regime Group 4-A. | FEIS: 2020 LANDFIRE Biophysical Settings [1] |
| Alters historical fuel characteristics of ecosystems where it occurs | Rarely/No | California flannelbush is a native component of chaparral and pinyon-juniper communities. It may carry surface or crown fires within stands but is not described as altering historical fuel characteristics. | FEIS: Fuel Characteristics [1] |
| Biophysical Setting | Mean Fire Interval (years) | Fire Severity Percent (%) | ||||||
|---|---|---|---|---|---|---|---|---|
| Code | Fire Regime Group | Low | Mixed | Replacement | All | Low | Mixed | Replacement |
| Series 11050 - Northern and Central California Dry-Mesic Chaparral | ||||||||
| 11050_3_6_7 | IV-A | 74 | 74 | 0 | 0 | 100 | ||
| 11050_4_5 | IV-A | 50 | 50 | 0 | 0 | 100 | ||
| Series 10190 - Great Basin Pinyon-Juniper Woodland | ||||||||
| 10190_4 | V-A | 814 | 467 | 640 | 203 | 25 | 43 | 32 |
| 10190_6_7_9_12_16_17_18_19 | V-A | 898 | 865 | 440 | 0 | 49 | 51 | |
| Series 11080 - Sonora-Mojave Semi-Desert Chaparral | ||||||||
| 11080_4_5_13_14_15_24_25 | IV-A | 81 | 81 | 0 | 0 | 100 | ||
| Series 10980 - California Montane Woodland and Chaparral | ||||||||
| 10980_3 | I-C | 54 | 94 | 34 | 0 | 63 | 37 | |
| 10980_6 | I-C | 54 | 92 | 34 | 0 | 63 | 37 | |
| Series 10990 - California Xeric Serpentine Chaparral | ||||||||
| 10990_4 | IV-A | 81 | 81 | 0 | 0 | 100 | ||
| 10990_3 | IV-A | 80 | 80 | 0 | 0 | 100 | ||
| Series 10340 - Mediterranean California Mesic Serpentine Woodland and Chaparral | ||||||||
| 10340_4_6_7 | III-A | 108 | 182 | 68 | 0 | 63 | 37 | |
| Series 10820 - Mojave Mid-Elevation Mixed Desert Scrub | ||||||||
| 10820_4_13 | V-A | 399 | 399 | 0 | 0 | 100 | ||
| 10820_6 | V-B | 516 | 516 | 0 | 0 | 100 | ||
| Series 11100 - Southern California Dry-Mesic Chaparral | ||||||||
| 11100_4 | IV-A | 51 | 51 | 0 | 0 | 100 | ||
| Series 11280 - Northern California Coastal Scrub | ||||||||
| 11280_2_3_4 | IV-B | 110 | 110 | 0 | 0 | 100 | ||
| Series 11030 - Great Basin Semi-Desert Chaparral | ||||||||
| 11030_6_7_12_13_16_17_23 | IV-A | 50 | 50 | 0 | 0 | 100 | ||
| Series 11130 - California Coastal Live Oak Woodland and Savanna | ||||||||
| 11130_3 | I-B | 27 | 31 | 174 | 13 | 50 | 42 | 8 |
| 11130_4 | I-B | 27 | 31 | 175 | 13 | 50 | 42 | 8 |
| Series 11140 - California Lower Montane Blue Oak-Foothill Pine Woodland and Savanna | ||||||||
| 11140_3_6_7 | I-B | 10 | 572 | 128 | 9 | 91 | 2 | 7 |
| 11140_4_5 | I-B | 14 | 150 | 127 | 12 | 83 | 8 | 9 |
| Series 10170 - Columbia Plateau Western Juniper Woodland and Savanna | ||||||||
| 10170_6_7_8_9_12_18 | III-B | 272 | 445 | 169 | 0 | 62 | 38 | |
| Series 10210 - Klamath-Siskiyou Lower Montane Serpentine Mixed Conifer Woodland | ||||||||
| 10210_2_3_6_7 | I-B | 11 | 70 | 229 | 9 | 82 | 13 | 5 |
| Series 10220 - Klamath-Siskiyou Upper Montane Serpentine Mixed Conifer Woodland | ||||||||
| 10220_2_3_6_7 | I-B | 11 | 70 | 231 | 9 | 82 | 13 | 5 |
| Series 10290 - Mediterranean California Mixed Oak Woodland | ||||||||
| 10290_2_3_4_5_6_7_12 | I-B | 11 | 33 | 285 | 8 | 72 | 25 | 3 |
| Series 11180 - Southern California Oak Woodland and Savanna | ||||||||
| 11180_4 | I-C | 30 | 43 | 173 | 16 | 54 | 37 | 9 |
| Series 11040 - Mogollon Chaparral | ||||||||
| 11040_13_14_25 | IV-A | 77 | 77 | 0 | 0 | 100 | ||
| 11040_15 | IV-A | 2171 | 80 | 77 | 4 | 0 | 96 | |
| Summary | ||||||||
| Minimum | 10 | 31 | 50 | 8 | 0 | 0 | 3 | |
| Maximum | 2171 | 898 | 865 | 516 | 91 | 63 | 100 | |
| Mean | 313 | 204 | 211 | 103 | 23 | 20 | 57 | |
| Median | 21 | 70 | 128 | 60 | 0 | 5 | 45 | |
| Percentage of fires in 3 fire severity classes, derived from LANDFIRE succession modeling. Replacement-severity fires cause >75% kill or top-kill of the upper canopy layer; mixed-severity fires cause 26%-75%; low-severity fires cause <26%. | ||||||||
| LANDFIRE. 2020. Biophysical settings models and descriptions, [Online]. Washington, DC: U.S. Department of Agriculture, Forest Service; U.S. Department of the Interior; U.S. Geological Survey; Arlington, VA: The Nature Conservancy, (Producers). Available: https://www.landfirereview.org/search.php [96496] | ||||||||
1. Abrahamson, Ilana L. 2021. Fremontodendron californicum, California flannelbush. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Missoula Fire Sciences Laboratory (Producer). Available: https://research.fs.usda.gov/feis/species-reviews/frecal
Last updated August 24, 2026