bigleaf lupine

not listed

N4N5 - Apparently Secure to Secure

SNR - Unranked

not listed

FACU - Facultative upland

FACU - Facultative upland

Bigleaf lupine is an erect, perennial forb that rises from a deep taproot. It can get from 20″ to 60″ tall, though in Minnesota it is usually 36″ to 40″ tall at maturity.

In the first year it develops a rosette of basal leaves. In the second year it sends up flowering stems. The stems are erect, unbranched, stout, round, and thinly hairy.

Stem leaves are alternate and are palmately divided into 11 to 17 leaflets. Lower leaves are on leaf stalks that are up to 17¾″ long, upper leaves are on shorter stalks.

The leaflets of the lower leaves are inversely lance-shaped, up to 6″ long and ⅝″ wide. The longest leaflets are about ½ as long as the leaf stalk. The upper surface is hairless or almost hairless. The lower surface is hairy. The margins are untoothed.

The inflorescence is a dense, cone-shaped, 8″ to 16″ tall spike with up to 80 flowers.

The individual flowers are ⅜″ to ⅝″ long. The 5 petals are shades of violet or blue and form a butterfly-like corolla, typical of plants in the Pea family. They are organized into a banner petal at the top, two lateral wing petals, and between the wings two petals fused into a keel. The banner is curved upward. There are 10 stamens; 5 with short filaments and long anthers, and 5 with long filaments and short anthers.

The fruit is a densely hairy, ¾″ to 2¼″ long pod containing 3 to 9 seeds. When ripe the pods open explosively, spreading the seeds a short distance.

36″ to 40″

Violet or blue

Moist. Forest edges, fields, shores, roadsides. Full sun to light shade.

June to July

Sources

2, 3, 4, 5, 7, 24, 28, 29, 30.

Most sources show this species restricted to just a handful of counties, mostly in the norhteast quarter of the state. The two sightings in the Metro Area (Washington and Dakota Counties) are from a county park and a private nature center. iNaturalist has many citizen sightings across a much broader range (light green on the map).

Native to the Alaska, Colorado, Idaho, Montana, Nevada, Oregon, Washington, and Wyoming. Introduced and escaped cultivation in the midwest.

Uncommon

Variety of a Subspecies
This is a variety of a subspecies, and some sources list it as Lupinus polyphyllus ssp. polyphyllus var. polyphyllus. The ICN (International Code of Nomenclature for algae, fungi, and plants), the rules governing the naming of plant species, makes it clear that this is not correct. Following ICN rules, a taxa “may also be referred to” with the inclusion of the intervening name (in this case, “ssp. polyphyllus”), but that does not constitute a formal name.

This is not a good picture, but helps to get the height. That is me in the photo. We just now took a ruler and measured 24 inches on me and they were definitely taller than that

We just returned from Madeline Island WI. The Lupine grow wild in abundance along the roads. Just gorgeous and in multiple colors.

Location: Madeline Island, WI

This is not a good picture, but helps to get the height. That is me in the photo. We just now took a ruler and measured 24 inches on me and they were definitely taller than that

Location: Madeline Island, WI

We just returned from Madeline Island WI. The Lupine grow wild in abundance along the roads. Just gorgeous and in multiple colors.