Montane, subalpine. Openings, woodlands. Summer. 
Above and left: Grand Mesa, July 11, 2017.

This robust Penstemon grows throughout the West, often, as shown on this page, in showy masses. Plants can grow to twenty inches tall with an abundance of blue-to-purple flowers.           

Aven Nelson named and described this species in 1898 from a collection he made near Laramie, Wyoming on July 1, 1897.

"Rydberg" honors the great 18th-19th century botanist, Per Axel Rydberg. Click to read biographical information about Rydberg.

Montane, subalpine. Openings, woodlands. Summer. 
Grand Mesa, July 11, 2017.

Flowers are in masses in the leaf axils and they are so numerous that they appear to be swirled around the stem. They are in a "verticillaster", a pair of cymes arising from the axils of opposite leaves and forming what looks like, but is not, a whorl.

As the second photograph at left shows, there can be (and most often are) several masses (several verticillasters) of flowers at different levels on the stem. Such flora arrangements are known as "interrupted inflorescences".

Montane, subalpine. Openings, woodlands. Summer. 
Grand Mesa, July 11, 2017.

Leaves are glabrous, and up to 7 inches long and a bit over an inch wide. As shown, they are about 4 inches long and 3/4 inch wide. Stem leaves are sessile, opposite, and typically elliptic to lanceolate to oblanceolate. Basal leaves (in clusters) have the same shape as stem leaves and are often petiolate (as can be the lowest stem leaves).