Erythranthe guttata aka Common Yellow Monkeyflower

Erythranthe guttata is native to western North America, ranging from Alaska south through British Columbia, the western United States (including California, Oregon, Washington, Idaho, Montana, Nevada, Colorado, Wyoming, and New Mexico) to northwestern Mexico (Chihuahua), with extensions reported into southern Mexico and South America. It occurs from sea level up to about 3,700 m (12,000 ft) in habitats as varied as Pacific splash zones, California chaparral, western U.S. deserts, alpine meadows, serpentine barrens, and the geysers of Yellowstone. The species has naturalized widely outside its native range, including across western and central Europe, parts of the eastern United States, Ecuador, Australia, and New Zealand.

In its native range it is associated with wet sites — stream banks, seeps, wetlands, and riparian zones — across plant communities including coastal scrub, chaparral, foothill woodland, valley grassland, and montane to subalpine forests, at elevations of roughly 1,000–9,500 ft (305–2,900 m). Outside its native range it is naturalized in much of Europe (e.g. Britain, France, Germany), eastern North America, Australia, and New Zealand, almost always near water.

Flowers are tubular, bright yellow, 2–4.5 cm long, and bilaterally symmetrical, with an upper lip of two lobes and a lower lip of three. The lower lip typically bears one large to many small red to reddish-brown spots — the source of the name guttata, Latin for "spotted." The corolla throat is constricted with a well-developed bearded palate, and the calyx enlarges in fruit with broadly triangular lobes. Bloom time is reported as spring at low elevations and summer at high elevations, with regional records of July–August (SEINet, southwestern U.S.) and June through early autumn (Calflora, California).

Erythranthe guttata is treated as a species complex, and many entities historically described as varieties or subspecies (such as Mimulus langsdorffii, M. nasutus, M. decorus, M. clementinus, M. cupriphilus, and M. lyratus) are now treated as synonyms or distinct species. Plants of the World Online lists 32 synonyms total under E. guttata. There are no widely recognized horticultural cultivars covered in standard botanical references for this species.

The perennial form of E. guttata spreads vegetatively via stolons or rhizomes, and stems can root at the nodes when in contact with moist soil. Standard botanical references do not detail seed-propagation protocols, though the species' status as a model organism implies seed propagation is routine in research settings.

Common yellow monkeyflower is bee-pollinated, with Bombus (bumblebee) species highlighted as principal pollinators. The bilaterally symmetrical, palate-bearing flowers are typical of bee-adapted Lamiales.

The species is defended against herbivores by physically resistant trichomes that have been examined in considerable detail in the scientific literature. Standard botanical references do not list specific cultivated-plant pests or diseases for this species.

The leaves of E. guttata are edible both raw and cooked; they are sometimes used as a lettuce substitute in salads and have a slightly bitter flavour.

Beyond ornamental and minor edible use, E. guttata is best known as a model organism for biological research. It is the subject of roughly 1,000 scientific papers studying evolution, genetics, ecology, and plant-insect interactions, and is widely used in research on adaptation to extreme habitats such as serpentine soils and copper-mine tailings.

Common Yellow Monkeyflower should be watered regularly, allowing the soil to dry out between waterings.

Common Yellow Monkeyflower requires abundant, bright, and direct light to thrive. The best placement for this plant is within one foot of a window to ensure it receives enough light. If you live in an area with more extreme weather, such as hot summers or cold winters, you may need to adjust the placement of the plant accordingly. During hot summer months, it is important to place the plant away from full sun, as this can cause the leaves to yellow or burn. During cold winter months, it is best to move the plant closer to the window to take advantage of the extra light that can help it survive. By keeping an eye on the current weather in your area, you can make sure your Seep Monkeyflower is always in the right place to thrive.

Ploi lacks confirmed information on the toxicity of this plant. If you, a relative, or your pet accidentally consume plant material with unknown toxicity, it's best to consult a medical expert.