Penstemon rydbergii A.Nelson

Nomenclature

Penstemon rydbergii A.Nelson, commonly known as meadow penstemon, typically grows two types of stems: short leaf-only stems and taller stems that terminate in an inflorescence.

Caudex and Root Structure

All of its herbaceous stems grow from a branching, woody caudex, which is usually positioned above a taproot.

Flowering Stem Height

Flowering stems are most often 20 to 70 centimeters (8 to 27.5 inches) tall, but can occasionally reach up to 1.2 meters (3 feet 11 inches).

Stem Growth Habit

Stems may grow straight upward, grow outward before curving upward, or grow along the ground.

Stem Hairiness

All stems can be either hairy or hairless; sometimes hairs are only present in lines on the stems below leaf attachment points.

Stem Coloration

Very often, stems become progressively more red toward the top.

Basal Leaf Arrangement

Most of the plant's leaves are basal, growing at the base of the plant and attached to the non-flowering stems.

Basal Leaf Length

Basal leaves and the lowest leaves on flowering stems are 2.5 to 15 centimeters (1 to 6 inches) long, most commonly 3.5 to 7 centimeters (1.5 to 3 inches) long.

Basal Leaf Width

They are 0.5 to 2.2 centimeters wide, most commonly 1 to 1.5 centimeters wide.

Basal Leaf Shape

Their shape ranges from oblanceolate to elliptic, with tapered bases and a narrow to broadly angled tip, and they are very rarely mucronate.

Cauline Leaf Length

Leaves attached to flowering stems grow in three to six opposite pairs, and are 2.5 to 11 centimeters (1 to 4 inches) long, usually shorter than 7 centimeters.

Cauline Leaf Shape and Width

They are 0.3 to 2.4 centimeters wide, and shaped lanceolate to elliptic or oblong.

Inflorescence Structure

The inflorescence sits at the top of the stem and holds one to seven widely spaced groups of flowers called verticillasters; most stems have at least two of these flower groups.

Cyme Arrangement

Flowers face all directions outward from two cymes, which are branches from a single attachment point, each holding three to eleven flowers.

Flower Coloration

The spreading lobes of the flower are bright to deep blue or purple, while the flower tube is violet to blue-purple, and the flower never has colored guide lines.

Flower Hairiness

The flower is hairless everywhere except the lower lip, which has a white or golden beard.

Flower Length

Flowers are usually 10 to 16 millimeters long, but can sometimes grow up to 20 millimeters long.

Stamen and Staminode Characteristics

The longest pair of the four stamens reaches or extends past the opening of the flower, and the staminode is 6 to 7 millimeters long, reaching just to the flower mouth.

Fruit and Seed Characteristics

Its fruits are hairless capsules that measure 4 to 5 millimeters long by 3 to 4 millimeters wide, and contain numerous small seeds 0.6 to 1 millimeter in size.

Overall Distribution Range

Meadow penstemon is native to the western United States, ranging from the Rocky Mountains to the Pacific states.

Distribution in New Mexico

In New Mexico, it is only found in the northern mountainous areas of the state.

Distribution in Colorado

In Colorado, it is only found in the western mountainous portion of the state.

Distribution in Wyoming

In Wyoming, it is only recorded from Carbon and Fremont counties.

Distribution in Montana

In Montana, it is only recorded from four of the state's southwestern counties.

Distribution in Great Basin

It is found across almost all of the Great Basin, but does not occur in eastern Nevada.

Distribution in Idaho

It grows in southern Idaho, and is not found in the northern Idaho panhandle.

Distribution in Washington and Oregon

It generally does not grow west of the Cascade Mountains in Washington and Oregon.

Distribution in California

In California, it grows in the northern Coast Ranges, the Klamath Mountains, and the higher elevations of the central Sierra Nevada.

General Habitat

While most penstemon species prefer dry habitats, meadow penstemon is usually found in moist places such as near streams or in wet meadows.

Association with Pocket Gophers

Experimental evidence shows that meadow penstemon becomes more abundant in areas where northern pocket gophers (Thomomys talpoides) are active, and it often grows more densely along the edges of areas disturbed by these gophers.

Chemical Composition

This species contains four iridoids bound as glycosides: euphroside, plantarenaloside, aucubin, and geniposidic acid.

Horticultural Use

Although it produces small flowers, it is sometimes grown in gardens, particularly by gardeners in regions with moist climates.

Propagation Requirements

It is propagated by seed, and requires twelve weeks of cold-moist stratification to achieve good germination rates.