Comprehensive DescriptionRead full entry
General: Figwort Family (Scrophulariaceae). Penstemon or beardtongue species are perennial forbs or sub-shrubs to shrubs with attractive flowers. They are short to long-lived. Low beardtongue is recognized as having three subspecies: Penstemon humulis ssp. humilis, Penstemon humilis ssp. obtusifolius, and Penstemon humilis ssp. brevifolius. Cronquist et al. (1984) provides a key to separating these subspecies, plus provides a short discussion of their ranges and characteristics.
Low penstemon is an herbaceous to woody subshrub perennial from 0.5 to 2.5 (sometimes 3.5) dm tall with well-developed basal leaves, usually forming mats. Generally, penstemons have opposite, entire, or toothed leaves. They have several stalked flowers or flower clusters that are borne in the axils of the upper leaves or leaf-like bracts. The tubular corolla is strongly to distinctly two-lipped at the mouth with a two-lobed upper lip and a three-lobed lower lip. There are 4 anther-bearing (fertile) stamens and a single sterile stamen or staminodia that is often hairy at the tip. The fruit is a many-seeded capsule.