Southwest Colorado Wildflowers, Lupinus polyphyllus

In hot dry areas, some species of Lupine may be sparse, short, and have few flowers; in moist woods other Lupine become luxuriously bushy, tall, with numerous flowers. Lupines have a long flowering period and they are one of the most eye-catching flowering plants in the Four Corners area. (They also provide magnificent displays in many other areas, e.g., the Blue Bonnets of Texas and the Bush Lupine of the California coast). In the Four Corners, look for some Lupines such as L. caudatus flowering in March and April and others such as L. argenteus flowering into September. All of the Four Corners Lupines have numerous (often dozens of) blue/purple, five-part flowers making up long (often numerous) racemes.

Because they hybridize, exact species identification of Lupines is often exceedingly difficult: Intermountain Flora states, "The taxonomy of the small-flowered perennial lupines is notoriously difficult. No sexual incompatibilities interfere with free genesis of fertile hybrids which blur the already precarious distinctions...." Utah flora expert Stanley Welsh says, "The genus [Lupinus] is notoriously difficult because of lack of clear diagnostic features."

Linnaeus named this genus in 1753. "Lupinus" (Latin for "Wolf") was so named because of the erroneous belief that the species degraded land.

Lupinus prunophilus. Synonym: Lupinus polyphyllus. (Lupine)
Fabaceae (Pea Family)

Foothills. Woodlands, openings. Spring, summer.
Lone Mesa State Park, May 14, 2009.

Such Lupine as the one pictured on this page are among the most robust, thickly flowering wild plants. They flower in wet and dry areas for extended periods. But they are often quite difficult to precisely identify. The pictured Lupinus polyphyllus has a number of characteristics that vary enough to produce numerous varieties. In addition, the characteristics that separate this species from several other tall, robust species of Lupine, such as, L. argenteus, L. ammophilus, and L. prunophilus are not markedly different. All of this makes for difficult times in identifying the exact species -- if indeed they are distinct species.

Lupinus polyphyllus was named by Lindley in 1827 from plants raised from seeds collected by David Douglas (of Douglas Fir fame).

Lupinus prunophilus. Synonym: Lupinus polyphyllus. (Lupine)
Fabaceae (Pea Family)

Foothills. Woodlands, openings. Spring, summer.
Lone Mesa State Park, May 14, 2009.

Most leaves on this plant were rolled tightly inward.

Lupinus prunophilus. Synonym: Lupinus polyphyllus. (Lupine)
Fabaceae (Pea Family)

Foothills. Woodlands, openings. Spring, summer.
Lone Mesa State Park, May 14, 2009.

The angle between the banner (the upright petal with the white center) and the wings (the horizontal petal in light purple) is often key in distinguishing among species. Look at the flowers in the bottom right corner and you will see that this angle is about 90 degrees. In some Lupine the angle might be just 30-45 degrees. But notice that the angle between the banner and the wings in the flower in the upper right corner is only about 60 degrees. These upper flowers are not fully opened.

Lupinus prunophilus. Synonym: Lupinus polyphyllus. (Lupine)
Fabaceae (Pea Family)

Foothills. Woodlands, openings. Spring, summer.
Lone Mesa State Park, May 14, 2009.

Hairiness varies: Some leaves that I examined on this plant were hairy both on their upper and lower surfaces; some were hairy only on their lower surface.