IngredientsThe accepted scientific name of yerba mansa is Anemopsis californica, with synonyms including Anemia californica and varietal designations Anemopsis californica var. californica and Anemopsis californica var. subglabra. The plant belongs to the family Saururaceae, the Lizard's-tail family. It is one of only six plants in the global Saururaceae family and is singular in the genus Anemopsis. Considered to be a paleo-herb, yerba mansa is ancient and believed to be close to the origins of monocotyledons.
Yerba mansa was formerly placed within the dicot angiosperms, but recent revisions to traditional taxonomy have separated it along with other more primitive plants into a group called the primitive dicots or basal dicots. It is a unique-looking perennial herb that often forms large mats from horizontal stems (stolons and rhizomes) that spread at or just below ground level.
Common English and Spanish names include "Yerba Mansa," "Lizard's Tail," and "Yerba del Manso" (also spelled "Hierba del Mansa" and "Yerba del Manzo"). In English, it is frequently called "lizard tail," owing to the elongated, tail-like shape of its inflorescence, and "swamp root," which highlights its preference for moist, wetland environments.
Indigenous names are numerous and tribe-specific. Documented indigenous names include vavish (Pima), chivnish (Cahuilla), 'onchoshi (Chumash), matacha (Acoma and Laguna Pueblos), cahpanï-l (Tübatulabal), wawic (Papago), cheu-pahn-iv (Moapa Piute), and chew-pon-iv (Shoshone).
Yerba mansa is native to the American Southwest and adjacent regions of the Southern Plains and Mexico. Its range includes the US states of Oregon, California, Nevada, Utah, Arizona, Colorado, New Mexico, Nebraska, Kansas, Oklahoma, and Texas. It is also native throughout Baja California and central and northern Mexico.
Yerba mansa is classified as a wetlands obligate throughout much of its range and is found in bosque (riparian floodplains), ciénega (spring-fed wet meadows), and other wetland habitats. It is a hearty groundcover that spreads rhizomatously and stoloniferously but requires a high water table, surface flows, or otherwise consistently moist soil for establishment and reproduction. Its preferred habitat is wet, saline or alkaline soils, wet or moist areas, seeps and springs.
The plant often forms large mats from horizontal stems (stolons and rhizomes) that spread at or just below ground level. Clumps of leaves are produced and root at discrete nodes along these stems, much like a strawberry plant. Leaves may stand two or three feet (75 cm) high, but are usually shorter. Long petioles support oval or elliptical blades that are smooth and almost rubbery in appearance. The plant has a woody rootstock and aromatic rhizomes. The flowers lack a perianth and form a conical-shaped head subtended by four to eight unequal, white, petal-like bracts.
All parts of the plant are aromatic. The scent has been described as "a cross between camphor and eucalyptus," "deep, woody," and "spicy." The precise aroma varies.
Flowering season extends from May to August, with variation by region. The plant grows at elevations ranging from 2,000 to 5,500 feet, with variation by state and region.
Both the roots/rhizomes and aerial parts are used medicinally; however, the roots/rhizomes are more potent than the leaves. Leaves, flowering tops, and stems are also employed in various preparations.
Products such as tea, tincture, and infusion have been utilized to alleviate the inflammatory injury of mucous membranes, swollen gums, and sore throats. Poultices of fresh or powdered plant material, decoctions of the root taken internally, and topical washes and antiseptic baths represent the principal traditional delivery forms. The root may also be chewed directly.
The root of the plant was used as a medicine by many tribes in California, the Great Basin, and the Southwest, including the Wukchumni Yokuts, Kawaiisu, Paiute, Shoshone, and Pima. Some Native Americans still gather the plant today.
The Kawaiisu boiled the root, and the resulting decoction was then drunk hot to alleviate colds and coughing. The Tubatulabal of southern California also took a decoction of the plant for colds.
In his master's thesis, Volney H. Jones described how the Isleta used yerba mansa leaves powdered for burns and wounds, or chewed fresh and applied as a poultice to burns (1931). George R. Swank documented similar uses for the herb by the Acoma and Laguna Peoples in his thesis The Ethnobotany of the Acoma and Laguna Indians (1932).
Ethnobotanists Julian Steward and Shirley C. Tucker (1933, 1941) took note of how Paiute, Shoshone, and Washoe Peoples traditionally boiled the leaves as a bath for muscular pain and achy feet; mashed the decocted roots and applied them as a poultice for swellings or used them as an antiseptic wash; and used a root decoction for upset stomach.
The Kamia of Imperial Valley pulverized the seeds of yerba mansa in a mortar, and the meal was then cooked as mush in a pot or baked as bread in hot ashes.
The aromatic rootstock was put to many medicinal uses: treatment of abrasions, cuts, and burns; a cure for a variety of gastrointestinal upsets; a poultice for rheumatism; and a tonic for blood purification.
In the eclectic medical tradition, as recorded in King's American Dispensatory (1898), the decoction was freely used in irritative disorders of the gastro-intestinal tract and urinary apparatus, particularly strangury. As a poultice, the root was applied to painful inflammatory swellings and to various kinds of abscess.
Topical preparations of Anemopsis californica have been used by Native American tribes in the southwestern United States and northern Mexico to treat inflammation and infections.
Many Native nations in California and the Southwest use the root of the plant as a medicine.
Traditional use extended across a broad range of ailments: respiratory conditions (colds, cough, bronchitis), gastrointestinal complaints, urinary tract problems, wound and skin care, and musculoskeletal pain. Medicinal applications for yerba mansa include respiratory, digestive, and urinary system ailments.
This plant was introduced to the [eclectic medical] profession by Dr. W. H. George, of California. The eclectic physicians of the 19th century noted its use for mucosal irritation and urinary conditions, and the plant's description in King's American Dispensatory (1898) represents one of the earliest formal Western medical records of its application.
The essential oil of A. californica roots and rhizomes has been the subject of multiple phytochemical investigations. The constituents of the hydrodistilled essential oil from the roots and rhizomes have been examined. Thymol was identified from the phenolic fraction of the oil. Gas chromatographic analysis confirmed the presence of methyleugenol as the major constituent. A third constituent of the oil was found to be piperitone. Methyleugenol (approximately 55 percent v/v of the oil), thymol (13 percent), and piperitone (5 percent) together make up approximately 74 percent of the oil.
Populations of A. californica collected throughout New Mexico were examined for chemical variability in roots and rhizomes for select monocyclic (cymene, limonene, piperitone and thymol) and bicyclic (α-pinene, 1,8-cineole and myrtenol) monoterpenoid and phenylpropanoid (methyleugenol, isoeugenol and elemicin) derived essential oil components.
While the composition of the leaf volatiles varied with method of extraction, alpha-pinene, sabinene, beta-phellandrene, 1,8-cineole, piperitone, methyl eugenol, (E)-caryophyllene, and elemicin were usually present in readily detectable amounts.
Other volatile compounds including methyleugenol, pulegone, menthone, isomenthone, and spathulenol have been reported in various proportions.
A critical finding in the phytochemistry of this species is that its chemical profile is not uniform across its range. Three distinct chemotypes have been detected using hierarchical clustering analysis on the concentration of 10 different analytes across 17 populations. One chemotype is characterized by high elemicin concentrations, a second by high methyleugenol concentrations, and the third by high piperitone and thymol concentrations. This chemotypic variability has significant implications for the pharmacological activity and safety of commercial preparations, since the dominant bioactive constituent differs markedly between plant populations.
Medina-Holguin et al. (2007) determined that there are correlations between chemical concentration variability and environmental conditions such as temperature and precipitation, as well as different altitudes (elevation).
Major non-volatile metabolites belong to phenolic compounds, such as caffeic acid derivatives, especially rosmarinic acid, as well as several flavones and flavone glycosides including acacetin, tilianin, agastachoside, and a rare dimeric malonyl flavone (agastachin).
Stem methanolic extracts (SME) present higher total phenols (79.44 ± 3.50 mg GAE/g of dry weight) than leaf methanolic extracts (LME) (27.84 ± 0.98 mg GAE/g of dry weight). There is a correlation between total phenolic content and antioxidant activities.
The furofuran lignans sesamin and asarinin have been isolated from A. californica roots. Sesamin and asarinin are extracted at relatively high levels from roots (1.7–3.1 g/kg and 1.1–1.7 g/kg, respectively), but at lower levels from leaves (0.13 g/kg for both compounds). Early chemical analysis also revealed 4-allylveratrole and (+)-asarinin from roots and rhizomes.
In vitro studies using lipopolysaccharide (LPS)-induced macrophages and ultraviolet B (UVB)-irradiated dermal fibroblasts have characterized the molecular mechanisms of A. californica extracts. Results showed that AC decreased the mRNA levels of inflammatory mediators in sensitized macrophages, including cytokines, inducible nitric oxide synthase (iNOS), and cyclooxygenase (COX-2). Moreover, AC alleviated UVB-induced photoaging in dermal fibroblasts by restoring procollagen synthesis.
These effects resulted from the regulation of excessive reactive oxygen species (ROS) mediated by the activation of the antioxidative system nuclear factor erythroid 2-related factor 2 (NRF2). AC also alleviated oxidative stress and inflammatory responses by inhibiting the phosphorylation of mitogen-activated protein kinase (MAPK) and interfering with the nuclear translocation of the immune regulator nuclear factor of activated T-cells 1 (NFATc1).
Studies have evaluated the antioxidant activity in relation to the mutagenic and antimutagenic activity properties of leaf and stem methanolic extracts of A. californica. Antioxidant properties and total phenols were evaluated using DPPH and Folin-Ciocalteu methods. Elastase inhibitory effects of 75% (leaf) and 71.8% (rhizome) have been documented, providing a basis for further research into anti-inflammatory activity.
The majority of activity of A. californica root extracts against nontuberculous mycobacteria can be attributed to the presence of relatively high levels of sesamin and asarinin. The presence of anti-mycobacterial compounds in roots supports the traditional use of this plant as a treatment for infection, although follow-up studies would be necessary to evaluate the in vivo relevance of these findings.
Steam-distilled leaf oil has demonstrated antimicrobial properties against three microbial species — Staphylococcus aureus, Streptococcus pneumoniae, and Geotrichum candidum — of eleven tested. Some of this bioactivity could be accounted for by the alpha-pinene in the oil.
Evidence type: In vitro/preclinical only. No human clinical trials identified.
A 2015 bioassay-guided isolation study (published in PMC/PubMed, PMC4586282) conducted on a sample of A. californica roots reported the isolation of the furofuran lignans sesamin and asarinin, which were shown to have minimum inhibitory concentration (MIC) values ranging from 23 to 395 µM against five different species of environmental nontuberculous mycobacteria. These findings were considered significant given that these bacteria can cause skin, pulmonary, and lymphatic infections.
In a comparative study of anti-Staphylococcus aureus activity, Anemopsis californica gave an MIC value of 360 µg/mL and a 10⁴-fold reduction in bacterial growth, placing it in a moderate efficacy category compared to other medicinal plants tested.
Strength of evidence: Preliminary; confined to in vitro and laboratory conditions. No human trials have been conducted.
Evidence type: In vitro/cell-based. No human clinical trials identified.
A 2021 in vitro study (published in Antioxidants, doi:10.3390/antiox10121882) investigated the photoprotective effects of A. californica extract in two in vitro models — LPS-induced macrophages and UVB-irradiated dermal fibroblasts. Results showed that AC decreased the mRNA levels of inflammatory mediators in sensitized macrophages, including cytokines, iNOS, and COX-2, and alleviated UVB-induced photoaging in dermal fibroblasts by restoring procollagen synthesis. The protective effects of AC on skin cellular components suggested potential for use in the development of drugs and cosmetics that protect the skin from UVB-induced chronic inflammation and aging.
The inhibition of the elastase enzyme was evaluated in leaf, stem, and rhizome methanolic extracts. The results demonstrated that extracts of A. californica maintain approximately up to 97 and 95% stability in phenolic content and antioxidant activity, respectively, when stored during 60 days at −20°C in the dark. Additionally, these extracts, principally from leaf and rhizome, showed an elastase inhibitory effect of 75 and 71.8%, respectively. Elastase inhibition is pharmacologically relevant to anti-inflammatory effects, particularly in the context of tissue degradation.
Strength of evidence: Preclinical; entirely in vitro. Mechanistic pathways (MAPK, NRF2, NFATc1, COX-2 suppression) have been identified but require confirmation in animal models and human trials.
Evidence type: In vitro. No human clinical trials identified.
The antioxidant activity in relation to the mutagenic and antimutagenic activity properties of leaf (LME) and stem (SME) methanolic extracts of A. californica were evaluated using DPPH and Folin-Ciocalteu methods. SME presented the highest antioxidant capacity and total phenolic content. Phenolic compounds serve to improve the antioxidant properties of the plants, and in the majority of studies they are correlated with antioxidant capacity.
Antioxidant activity is a documented property of A. californica essential oil (ACO). However, ACO possesses volatile compounds that provide strong flavors and that are susceptible to degradation, complicating its application. An alternative approach of encapsulating it in a β-cyclodextrin (β-CD) matrix has been investigated.
Strength of evidence: Preliminary; entirely in vitro using standard radical-scavenging assays. No in vivo or clinical antioxidant studies are available.
Evidence type: In vitro (Ames test and cell-based assays). No human clinical trials identified.
Mutagenicity was evaluated using the Ames test employing Salmonella enterica serovar Typhimurium strains (TA98, TA100, and TA102), with and without metabolic activation (S9 mixture). Antimutagenesis was performed against mutations induced with MNNG, 2AA, or 4NQO. SME presented the highest antioxidant capacity and total phenolic content. None of the extracts exhibited mutagenicity in the Ames test. The extracts produced a significant reduction in 2AA-induced mutations in S. typhimurium TA98.
The results of this study showed that A. californica did not induce any point mutations in the S. typhimurium Ames test. These results suggest that the leaf and stem methanolic extracts of A. californica may be safe for use in humans and should be considered for further medical development studies.
The antioxidant properties and capacity to reduce point mutations may render it suitable to enhance medical cancer treatments. The significant effect against the antimutagenic action of 2AA suggests that their consumption would provide protection against carcinogenic polycyclic aromatic compounds.
Strength of evidence: Preliminary; purely in vitro. Findings require follow-up in animal and human studies before any clinical conclusions can be drawn.
Evidence type: In vitro (cell lines). No human clinical trials identified.
Steam-distilled oil from A. californica roots was used to screen for anticancer bioactivity. Root oils demonstrated anti-proliferative activity against AN3CA (endometrial) and HeLa (cervical) cells in vitro, but no activity against lung, breast, prostate, or colon cancer cells. The IC50 values for the root oil were 0.056% and 0.052% (v/v) for the AN3CA and HeLa cells, respectively.
Strength of evidence: Highly preliminary; limited to in vitro cell-line data with no animal or clinical studies to support translation to therapeutic use.
Evidence type: Traditional use only. No clinical studies identified.
Multiple indigenous traditions document the use of yerba mansa root decoctions for colds, cough, and respiratory infections. The Kawaiisu boiled the root and drank the decoction hot to alleviate colds and coughing. The Tubatulabal of southern California also took a decoction of the plant for colds. No controlled clinical studies assessing yerba mansa for respiratory conditions have been located in the peer-reviewed literature.
Evidence type: Traditional use only. No clinical studies identified.
In the eclectic medical tradition, the decoction was freely used in irritative disorders of the gastro-intestinal tract and urinary apparatus, particularly strangury. These indications derive from historical eclectic practice and Native American ethnobotany, with no corroborating controlled clinical evidence.
No standardized dosage protocols have been established through modern clinical trials for any indication. The following represent dosage forms and contexts noted in available sources:
The most notable toxicological concern associated with A. californica is its content of methyleugenol, a phenylpropanoid that is the dominant volatile constituent in some chemotypes. The essential oil of this species has been extensively studied, revealing that the oils extracted from its leaves and roots contain high percentages of methyleugenol and elemicin. t-Anethole was also detected. Methyleugenol is classified as a possible carcinogen in high-dose rodent studies, but traditional-use doses are described as far below thresholds of concern. No formal risk assessment for methyleugenol exposure specifically from yerba mansa preparations has been published in the peer-reviewed literature.
A concerning characteristic of A. californica is that the plants are known to readily absorb arsenic and other heavy metals from groundwater, which pose a serious health threat to users of ethnobotanical medicinal preparations made from the roots/rhizomes of this species. This is particularly relevant for plants harvested from contaminated or industrial-adjacent wetland habitats.
There are not many studies on the safety of its use or the effects it may have on DNA. However, the results of one published study showed that A. californica did not induce any point mutations in the S. typhimurium Ames test. These results suggest that the leaf and stem methanolic extracts of A. californica may be safe for use in humans and should be considered for further medical development studies. It should be noted that these findings pertain to specific extract types and cannot be generalized to all preparations or chemotypes.
Both the roots/rhizomes and aerial parts are used medicinally; however, the roots/rhizomes are more potent than the leaves. The minimum lethal dose (LD50) for the roots/rhizomes is 316 mg/kg, while the aerial parts showed no lethality even at doses up to 1 g/kg in animal testing. This differential potency should inform the appropriate plant part selected for preparations.
Three distinct chemotypes have been recorded for A. californica, differentiated according to their methyleugenol, elemicin, and thymol/piperitone content. Because chemical profiles vary substantially across populations and growing environments, the safety and pharmacological profile of commercial preparations may vary significantly depending on the geographic origin and chemotype of the plant material used.
Little information concerning the bioactive compounds and antioxidant activities of the stems and leaves of A. californica grown in Mexico is available. The plant has been widely used and is empirically proven as a medicinal plant. However, there are not many studies on the safety of its use or the effects it may have on DNA. No formal pharmacokinetic, pharmacodynamic, or drug-interaction studies have been identified in the peer-reviewed literature. No regulatory body (FDA, EMA, WHO, EFSA) has issued a formal safety monograph for yerba mansa as a dietary supplement ingredient.
United Plant Savers classifies Anemopsis californica as an "At-Risk" species. Yerba mansa is classified as a wetlands obligate throughout much of its range and is found in bosque (riparian floodplains), ciénega (spring-fed wet meadows), and other wetland habitats. Riparian forest (bosque) and spring-supported bog (ciénega) habitats cover only a very small percentage of land within its range. Desert bosque environments including the Rio Grande and the Colorado River are considered to be among the most severely altered and endangered ecosystems anywhere. The plant is critically threatened by habitat loss, with 60% habitat reduction reported along the Rio Grande.
Health conditions that Yerba mansa may help support.
Body systems that Yerba mansa may help support.
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