This penstemon has reasonably attractive flowers, and should be cultivated in wildflower gardens more often. Long-Sepaled Penstemon resembles Penstemon digitalis (Foxglove Penstemon) somewhat, but it is usually a little smaller and has light violet or purple flowers, while Foxglove Penstemon has white flowers that are at most tinged with violet. Long-Sepaled Penstemon also has longer sepals, and its anthers lack small tufts of white hair, unlike the latter species. Other features to consider while identifying a penstemon species include the presence or absence of ridges on the lower inner surface of the corolla, and the presence or absence of hairs on the leaves.