Mimulus ringens is a species of monkeyflower known by the common names Allegheny monkeyflower and square-stemmed monkeyflower.
It is native to eastern and central North America and has been introduced to the Pacific Northwest.[1] [2] It grows in a wide variety of moist to wet habitat types.[3] [4] Seeds are available from commercial suppliers.
This is a rhizomatous perennial growing 20cm (10inches) to well over 1meter tall, its 4-angled stem usually erect. The oppositely arranged leaves are lance-shaped to oblong, up to 8cm (03inches) long, usually clasping the stem. The sessile leaves of M. ringens help to distinguish it from its eastern relative, Mimulus alatus,[5] which bears leaves on petioles and has a winged stem. The herbage is hairless. The flower is 1inches-3inchesin (-in) long, its tubular base encapsulated in a ribbed calyx of sepals with pointed lobes. The flower is lavender, blue, red or pink in color and is divided into an upper lip and a larger, swollen lower lip.
One variety of this plant, var. colophilus, is rare, ecologically restricted, and vulnerable. It is known from Quebec, it has been reported in Vermont, and there are a few occurrences in Maine, where it grows only in freshwater sections of tidal estuaries.[6] This variety is distinguished by having shorter calyces than the ringens variety and by its short flower pedicels, 1cm-1.7cmcm (00inches-00.7inchescm) long versus a length of 2cm-3.5cmcm (01inches-01.4inchescm) in the nominate subspecies. This plant variety faces several threats, but its current status is not known due to a lack of data.[6] [7] [8]