Paghat's Garden: 'Bashful' Beard-tongue - One of a series of plant portrait pages documenting penstemons in this Pacific Northwest garden. Varieties featured are 'Bashful', 'Prairie Dusk', 'Midnight Blue', 'Ruby', 'Apple Blossom', 'Sour Grapes', and 'Garnet'. The Penstemon Website - Enthusiast's collection of links, information (both for gardeners and botanists), and photographs of penstemon species and varieties. The Penstemons: Seed Germination Methodology - Two pages in Tom Clothier's plant germination database dedicated exclusively to penstemon species, which are often finnicky and require a wide variety of germination conditions. Las Pilitas: California Penstemons - Two pages with pictures, brief descriptions, and cultural requirements of penstemons native to California, for dry-area and moist-area species. Dave's Garden PlantFiles: Genus Penstemon - Index page with links to all species and varieties of penstemon listed in the PlantFiles database of member-provided plant information and photos. American Penstemon Society - Offers information about membership, library, publications, events, taxonomy, and illustrated identification characteristics. Kemper: Penstemon digitalis - Plant portrait of foxglove beardtongue with cultural information, photos, and noteworthy characteristics.