IngredientsThe common name "Purple Monkeyflower" is applied to more than one taxon within the broader monkeyflower group (genus Mimulus sensu lato, family Phrymaceae), and accurate use of this reference article requires distinguishing among the principal species it may denote.
Erythranthe purpurea is a species of monkeyflower known by the common name little purple monkeyflower. It was formerly known as Mimulus purpureus. Erythranthe purpurea is an annual herb that is native to California, and also found in Baja California, placed in the family Phrymaceae (formerly Scrophulariaceae). Alternate names include Mimulus purpureus var. purpureus and var. pauxillus.
Erythranthe purpurea is native to California, where it is known from only about 20 occurrences in the San Bernardino Mountains; it is also known from Baja California. It grows in moist habitat in mountain meadows, including the quartz pebble plain habitat type near Big Bear Lake.
Erythranthe purpurea is a petite annual herb growing just a few centimeters tall. The oppositely arranged oval leaves are under 2 centimeters long each. Each flower is borne on a very thin, erect pedicel which may be several centimeters tall. The tubular base of the flower is encapsulated in a reddish ribbed calyx of sepals with tiny pointed lobes. The flower is roughly a centimeter long with a wide mouth divided into an upper and lower lip.
The plant is an annual herb with elliptic to lanceolate leaf shape and palmate leaf venation, growing to about 4 inches in height, with fruit of capsule type.
Erythranthe lewisii (Lewis' monkeyflower, great purple monkeyflower) is a perennial plant in the family Phrymaceae, named in honor of explorer Meriwether Lewis. It was formerly known as Mimulus lewisii. It was given the scientific name Mimulus lewisii in 1813 by Frederick Traugott Pursh. It was moved to the genus Erythranthe in 2012 by Guy L. Nesom and Naomi Fraga. Together with its genus it is classified in the family Phrymaceae.
Erythranthe lewisii is a perennial herb, with stem length ranging from 25 to 80 cm and individual leaves ranging from 20 to 70 mm. The vegetative tissue is covered with fine hairs. The flowers are medium in size, set on fairly long (30–70 mm) pedicels, and range in color from pale pink (generally found in the Sierra Nevada populations, sometimes separated as Erythranthe erubescens) to dark magenta (more common in the Cascade Range and Rocky Mountains populations), with a central pair of carotenoid-rich yellow nectar guides covered in trichomes on the lower lobe of the corolla.
Erythranthe lewisii is native to western North America from Alaska to California to Colorado, where it grows in moist habitat such as stream banks, and is generally found at higher elevations in montane areas. Lewis's monkeyflower is a tall perennial forb, reaching a height of 3½ feet. It occurs commonly along mountain streamsides, often among rocks and boulders, from southeastern Alaska to Alberta and south to California, Utah, and Colorado.
The opposite leaves are distinctive in being sessile, coarsely toothed, and having prominent palmate veins. The flowers have 5 petals fused at the base into a short tube and flaring at the mouth into two weakly-defined lips. To Linnaeus, these lips had the appearance of a smile or grin, earning the genus its name Mimulus after mimus for a grinning comic actor. The "smiling corolla" may also account for the common name of monkeyflower, for its fanciful resemblance to a grinning simian.
The specific epithet lewisii is in honor of the early North American explorer Meriwether Lewis who collected and documented Mimulus lewisii on his iconic expeditions across the American West. Mimulus is derived from the Latin word mime, meaning "actor" or "mimic." This is most likely referring to the mask-like appearance of the flowers.
Over 100 species of Mimulus occur worldwide, with nearly 70% native to California and even more centered in the western United States. Most of these species are delicate annuals or have bright yellow flowers. A recent taxonomic treatment has split the genus Mimulus into at least three genera, placing the M. guttatus, M. luteus, and M. lewisii complexes in the genus Erythranthe, and the M. aurantiacus complex in the genus Diplacus. Despite this reclassification, the former genus name Mimulus remains widely used in both older literature and ongoing scientific research.
The common name "purple monkeyflower" is applied to several plants. The two most botanically prominent candidates for the name are E. purpurea (little purple monkeyflower, annual, rare, San Bernardino Mountains) and E. lewisii (great purple monkeyflower, perennial, widespread in western North America). A third important species, Erythranthe guttata (formerly Mimulus guttatus, common/yellow monkeyflower), is not typically called "purple" but is the primary species used in Bach flower remedies under the genus name Mimulus and carries the largest ethnobotanical and phytochemical research record; information from this species is included where clearly labelled and directly relevant to the monkeyflower genus.
Erythranthe purpurea (little purple monkeyflower) is ranked 1B.2 by the California Native Plant Society — Plants Rare, Threatened or Endangered in California and Elsewhere; Moderately threatened in California. It is native to California, where it is known from only about 20 occurrences in the San Bernardino Mountains, and it also occurs in Baja California. It grows in moist habitat in mountain meadows, including the quartz pebble plain habitat type near Big Bear Lake. This extreme rarity means wild collection of E. purpurea is ecologically inappropriate and likely legally restricted.
Erythranthe lewisii, by contrast, is not listed as rare or threatened and occurs widely across western North America. It occurs commonly along mountain streamsides, often among rocks and boulders, from southeastern Alaska to Alberta and south to California, Utah, and Colorado.
Among the species Lewis and Clark first documented was the brilliant pink, or reddish-purple flower, Lewis's monkeyflower (Mimulus lewisii). Frederick Pursh, the 19th-century botanist who identified most of the expedition's collections, named the species in Lewis's honor in an 1814 publication and included a handsome color print of the species, taken presumably from material gathered by Lewis. Based on their journals, the explorers encountered Mimulus lewisii "on the head springs of the Missouri [River], at the foot of Portage hill," a site interpreted as the head of Trail Creek, Montana, just below Lemhi Pass.
Erythranthe lewisii is pollinated by bees (primarily Bombus and Osmia), which feed off of its nectar and transfer its pollen. Although it is fully interfertile with its sister species, E. cardinalis, the two do not interbreed in the wild, a difference ascribed primarily to pollinator differences (E. cardinalis is pollinated by hummingbirds) in areas of overlap. This pollinator-based reproductive isolation has made E. lewisii an important model system in evolutionary biology.
Monkeyflower species, and particularly the closely related Erythranthe guttata (common/yellow monkeyflower), have a well-documented record of food use among Native American peoples across the western United States. These records, compiled in sources such as Daniel Moerman's Native American Ethnobotany (University of Michigan–Dearborn), describe use of the plant as a vegetable and food source:
The leaves of E. guttata are edible, both raw and cooked. Leaves are sometimes added to salads as a lettuce substitute. The young leaves and stems were eaten as salad greens or as potherbs. The older leaves are bitter and pungent. Because the plant easily absorbs sodium chloride salt from the soil, the ashes of the dried and burned leaves were used as a salt substitute.
The plant was used as a poultice for treating skin irritations and various minor burns, including rope burns. The Kumeyaay tribe used monkeyflower primarily for medicinal purposes, from poultices for burns and wounds to treatments for colds, coughs, flus, stomach disorders, and heart ailments. Among some Pacific Northwest peoples, the leaves were occasionally used in poultices for minor wounds and skin conditions.
A root concoction was used for treating epilepsy. A plant concoction was used as a wash to counteract poisons. These uses are documented in ethnobotanical records from related Mimulus species (M. ringens) in Indiana.
In the Crow Tobacco Ceremony, monkeyflower is mixed with moss and chokecherry flowers to form a compost for tobacco seeds. The plant is known to the Crow as baauhpà shiile, blooms at the same time the tobacco plant does, and is kept in a sacred bundle.
In Alaska, monkeyflower was known and observed by Alaska Native peoples as a reliable indicator of freshwater — streams lined with monkeyflower were reliable sources of drinking water.
The Cherokee used related eastern Mimulus species medicinally, suggesting a pan-North American awareness of the genus as medicinally useful.
The monkeyflower genus gained particular prominence in Western alternative medicine through the work of Dr. Edward Bach. The plant gained prominence in the early 20th century when Dr. Edward Bach, a British physician and homeopath, selected Mimulus as one of his original 38 Bach Flower Remedies. Bach believed that Mimulus could help address fears and anxieties of known origin, making it a cornerstone in emotional wellness therapies.
In Bach's system, the flower 'mimulus' is used for fear of known things, shyness, and timidity. It is described as the remedy for known fears: whenever one is frightened or anxious about something that can be named, Mimulus is indicated. Mimulus fears are those of everyday life — fear of public speaking, of the dark, of aggressive dogs, of illness and pain. Phobias can also be Mimulus fears if the cause of the fear can be named.
The Bach system uses Mimulus guttatus (common yellow monkeyflower) as the primary source plant, prepared by floating flowers on spring water in sunlight. In the Bach Flower Remedy system, a plant's unlocked energy is considered as therapeutically important as its biodynamic chemical components.
The bumblebee-pollinated Mimulus lewisii bears pink flowers colored by anthocyanins, except for the yellow nectar guides which result from carotenoid pigmentation. Anthocyanins are a class of flavonoid pigments with established antioxidant activity in the broader phytochemical literature, though no specific bioactivity studies on anthocyanins isolated from E. lewisii or E. purpurea have been identified in the peer-reviewed literature.
The genus Mimulus has been used as a model system in a wide range of ecological and evolutionary studies and contains many species with carotenoid-pigmented flowers. The detailed carotenoid composition of these flowers had not been reported until a focused investigation characterized the floral carotenoid composition of 11 Mimulus species using high-performance liquid chromatography, mass spectrometry, and chemical methods, with a particular focus on Mimulus lewisii.
M. lewisii flowers have five major carotenoids: antheraxanthin, violaxanthin, neoxanthin, and the unique allenic carotenoids, deepoxyneoxanthin and mimulaxanthin. This carotenoid profile is consistent with the expression levels of putative carotenoid biosynthetic genes in the M. lewisii flower. The other 10 species examined possess the same five carotenoids or a subset of these.
Of particular note, deepoxyneoxanthin and mimulaxanthin are described as unique allenic carotenoids, meaning they possess an allene (cumulated diene) structural feature that is uncommon among plant pigments. These compounds are chemically characterized but their specific pharmacological or nutritional activity in humans has not, to date, been established in clinical research.
Research on the closely related Erythranthe guttata (common yellow monkeyflower) has revealed an important class of secondary metabolites also relevant to the broader monkeyflower group. The foliage of yellow monkeyflower contains a diverse suite of phenylpropanoid glycosides (PPGs), a class of compounds with many known biological activities. Using ¹H and ¹³C NMR and UV and MS chromatography techniques, researchers positively identified five PPGs from the leaves of yellow monkeyflower.
PPGs originate from the shikimic acid-phenylpropanoid pathway and include simple monosaccharides, consisting of hydroxycinnamic acid and hydroxyphenylethyl moieties bonded to a central β-glucopyranose by ester and glycosidic linkages, respectively, and more complex di- and trisaccharides with one or two additional sugars linked to the core glucose.
Members of this compound class have shown a wide range of biological activity, including inhibition of plant pathogenic bacteria and fungi, antioxidant activity, tumor cell suppression, feeding stimulation of specialist herbivores, and deterrence of generalist insects. These activities, however, have been characterized for PPGs broadly, not exclusively for those isolated from monkeyflower species.
Four of the five identified compounds from M. guttatus occur in other plant species and one is previously undescribed. Researchers also presented UV and high-resolution tandem MS data that putatively identify 11 additional foliar compounds as PPGs. Earlier work by Bohm (1992) described flavonoids from the leaf exudate of Mimulus lewisii.
Some phytochemical studies have identified the presence of flavonoids, phenolic compounds, and other antioxidants in monkeyflower species, which are generally recognized for their potential to combat oxidative stress and support overall cellular health. Specifically, work referenced in the phytochemistry literature identified flavonoid glycosides including quercetin-3-O-D-glucoside, quercetin-3-O-D-xyloside, kaempferol-3-O-D-xyloside, and quercetin-3-O-D-(6″-coumaroyl)-galactoside in related species. Bohm (1992) specifically reported on exudate flavonoids of Mimulus lewisii.
The PPGs and flavonoids identified in monkeyflower species belong to compound classes with well-established antioxidant properties in the broader literature. However, no clinical or controlled human trials specifically assessing antioxidant effects of purple monkeyflower (E. purpurea or E. lewisii) preparations have been identified in the peer-reviewed literature.
PPGs of the class found in monkeyflower foliage have shown antioxidant activity in studies on this compound class generally. These findings are from in vitro research on the compound class, not from clinical trials of monkeyflower extracts in humans. Evidence strength: Preliminary/in vitro only; no human trials identified.
PPGs of the class found in monkeyflower foliage have demonstrated inhibition of plant pathogenic bacteria and fungi in studies on this compound class. Again, these findings pertain to the PPG compound class broadly. No antimicrobial clinical trials on monkeyflower preparations in humans have been identified. Evidence strength: Preliminary/in vitro for the compound class; no human data.
Traditional poultice use for minor wounds and burns is documented across multiple Native American groups as described in Section 4. However, no controlled clinical studies examining wound-healing effects of purple monkeyflower preparations have been located. Evidence strength: Ethnobotanical/traditional evidence only; no controlled human trials identified.
This is the area with the most clinical research on monkeyflower species, albeit conducted on multi-ingredient flower remedy preparations rather than monkeyflower alone.
Four randomised controlled trials (RCTs) and two additional retrospective, observational studies were identified and included in a systematic review. Three RCTs of Bach Flower Remedies for students with examination anxiety and one RCT for children with attention-deficit hyperactivity disorder (ADHD) showed no overall benefit in comparison to placebo. Due to the number and quality of the studies, the strength of the evidence is low or very low.
One German study randomized 61 students to a pre-determined combination of 10 Bach Flower Remedies (including impatiens, mimulus, gentian, chestnut bud, rock rose, larch, cherry plum, white chestnut, scleranthus, and elm) or placebo in a four-week cross-over design. This was, to the investigators' knowledge, the first trial examining the efficacy of a formula of Bach Flower Remedies for test anxiety.
Investigators rated five of the six included trials as being at high risk of bias. The evaluation of complementary and alternative medicine practices using evidence-based medicine principles is acknowledged to be controversial.
There is limited but promising evidence of a potential relationship between Bach Flower Remedies and a reduction in anxiety, and a suggestion that they may enhance quality of sleep.
Most of the available evidence regarding the efficacy and safety of Bach Flower Remedies has a high risk of bias.
Critically, all trials to date use multi-ingredient preparations in which Mimulus is one of several components; no trial isolates Mimulus alone. Evidence strength: Weak to very weak; available RCTs show no overall benefit vs. placebo; high risk of bias; no trials of monkeyflower as a single agent.
Ethnobotanical records document traditional use as a digestive aid (decoction for stomachache in Yavapai tradition), and as a food plant whose mildly bitter leaves were consumed by multiple groups. No controlled human trials examining gastrointestinal effects have been identified. Evidence strength: Ethnobotanical/traditional use only.
It is worth noting that the greatest body of rigorous scientific work on E. lewisii and related species concerns ecology, evolution, and genetics rather than human health applications. Together with other species in Erythranthe, E. lewisii serves as a model system for studying pollinator-based reproductive isolation. In the context of biological studies, Mimulus guttatus is still referred to as such and is a model organism. There may be as many as 1,000 scientific papers focused on this species. This large body of research is in genetics, evolution, and ecology — not in human pharmacology or nutrition.
The associations below are drawn from documented traditional use and phytochemical research. Where no human clinical evidence exists, this is explicitly stated.
In the Bach flower remedy system, Mimulus (typically prepared from M. guttatus) is commercially available as a liquid flower essence in an ethanol-preserved preparation. The Bach system suggests adding 2 drops of up to 7 remedies in a 30 ml / 1 oz treatment bottle.
No peer-reviewed dosage studies on purple monkeyflower preparations have been located. No standardized extract, clinical dosage protocol, or pharmacokinetic data for E. lewisii or E. purpurea as a dietary supplement have been identified in the authoritative literature. The Bach flower essence preparation is highly dilute and contains no measurable level of plant-derived chemical compounds by conventional analytical standards.
From a scientific perspective, research on the health benefits of monkeyflower remains limited. Clinical trials specifically involving monkeyflower extract in human populations are scarce, and its effects have not been conclusively demonstrated in rigorous scientific studies.
Multiple Native American groups consumed monkeyflower leaves (primarily of E. guttata) as food without documented adverse effects in the ethnobotanical record. Younger leaves are milder; older leaves are bitter and pungent. No toxicological studies specifically on E. lewisii or E. purpurea have been identified in the peer-reviewed literature.
Only four of the six studies included in the systematic review of Bach Flower Remedies for psychological problems and pain explicitly reported adverse events. The preparations are highly dilute, contain only trace-level botanical material if any, and the systematic review did not identify specific harms. However, the evidence base for safety is also weak and limited.
Erythranthe purpurea (little purple monkeyflower) is ranked 1B.2 — rare, threatened, or endangered in California and elsewhere — by the California Native Plant Society. Wild harvest of this species is therefore ecologically harmful and likely impermissible. Any commercial products claiming to use this specific taxon should be viewed with scrutiny regarding sourcing.
No drug interaction studies for purple monkeyflower preparations have been identified. More research is needed to fully validate and understand the efficacy and safety of monkeyflower preparations. The phytochemical profile — including flavonoids and PPGs — suggests theoretical potential for interactions with drugs metabolized similarly to other flavonoid-rich plants, but no such interactions have been documented for monkeyflower in the clinical literature.
Purple monkeyflower (across both its primary named species) is a botanically well-characterized native North American wildflower with a documented ethnobotanical record of food and medicinal use by numerous indigenous peoples. Its phytochemical profile includes unique and structurally interesting compounds — novel allenic carotenoids and phenylpropanoid glycosides — that have been characterized in laboratory research. However, the translational gap from phytochemistry to demonstrated human health benefit remains entirely unbridged for these specific species. No human clinical trials specifically investigating purple monkeyflower extracts as a dietary supplement or medicinal agent have been identified in the peer-reviewed biomedical literature. The only clinical trial evidence for monkeyflower in a health context comes from multi-ingredient Bach flower remedy studies, and that evidence consistently fails to demonstrate efficacy superior to placebo.
Although Mimulus is well established in traditional and holistic practices, robust scientific validation of its health benefits remains limited.
Health conditions that Purple monkeyflower may help support.
Body systems that Purple monkeyflower may help support.
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