A native perennial, toothleaf monkeyflower (Erythranthe dentata) is found along the western coast of North America from British Columbia through California. This member of the Lopseed family (Phrymaceae) grows along coastal streams and in moist, shady habitats up to 1,300 feet.
Growing from shallow, hairy rhizomes, toothleaf monkeyflowers are hairy plants with stiff, whitish hairs on the herbage. The opposite leaves are lanceolate to ovoid, veined and have toothed margins. The lower leaves have short petioles while the upper leaves are sessile.
The solitary, yellow toothleaf monkeyflower flowers arise from the leaf axil on long pedicels (stalks). The sepals are ribbed with pointed tips. The five petals are united into a tubular shape with two lips, the upper lip having two lobes and the lower having three lobes. The throat is spotted brown to reddish brown. The stamens number four.
Toothleaf monkeyflower fruits are capsules containing numerous seeds.
A synonym for E denatata is Mimulus dentatus. Another common name is coastal monkeyflower. The first named species in this genus was red, thus the genus name, from Greek, means red flower. The species designation, dentata, refers to the toothed leaf margins.
In May Leonard and I observed these toothleaf monkeyflowers along Fern Canyon Trail at Prairie Creek Redwoods State Park along the Northern California Coast.