Flower:

Elongating clusters at the tip of the stem and arising from leaf axils on the upper 1/3 or more of the stem. The clusters are initially compact and more or less triangular in shape, becoming arching as they stretch out, the stalkless flowers all crowded on the upper side of the cluster and blooming from the bottom up, with only 1 to a few flowers open on the cluster at a time. Flowers are ½ to ¾ inch long, blue to violet, sometimes pink or white, bell or funnel-shaped with 5 rounded lobes, the upper 2 extending farther than the lower 3. Outer surfaces are hairy, inner surfaces hairless. In the center are 5 long, curved, red to purple stamens with yellow tips and a red to purple style that's hairy on the lower half. The calyx has 5 lance-linear lobes that are shorter than the floral tube and covered in long, spreading hairs. At the base of each flower is a small, hairy, leaf-like bract about as long as the calyx.

Leaves and stems:

Leaves are basal and alternate, generally lance-linear, the lower to 6+ inches long, up to 1 inch wide and stalked, becoming smaller and stalkless as they ascend the stem. Edges are toothless, surfaces are covered in spreading, bristly hairs with sharp spines along the midrib on the underside. Leaves often become a bit wavy or twisted. Stems are single or multiple from the base, erect or the lateral stems ascending, green, covered in short, appressed hairs as well as long, spreading spines with purple, swollen bases that give a polka-dotted appearance.

Fruit:

Fruit is a cluster of 4 nutlets, though often only 1 or 2 reach maturity. Nutlets are about 2.5mm long, angular, gray-brown to blackish and covered in minute bumps.

Notes:

While Viper's Bugloss is quite striking, it might better be considered an “up and coming” weed in Minnesota. First collected in Grand Marais in 1892, it was rarely recorded until the early 2000s, when it started getting more notice along roadsides mostly near the north shore of Lake Superior. We first spotted it in 2013 along Highway 61 near Grand Marais among the Oxeye Daisies, Birds-foot Trefoil, Orange and Yellow Hawkweeds (aren't the wildflowers on the north shore pretty?), and Reed Canary-grass, and have watched its progression in the years since. While it is not yet widespread, it seems to be expanding its territory more rapidly now and is potentially invasive, currently listed as a noxious weed in the northwest US. Regardless of that status, it is a pest in any case due to the sharp spines on leaves and stems, which can embed themselves in skin much like a cactus. Plants also contains alkaloids that are toxic to horses, and while considered by some to be good for pollinators, honeybees that feed on it may produce honey that is mildly toxic. Viper's Bugloss is not likely to be confused with any other species; the flowers and their arrangement along with the spiny stems and leaves are pretty unique.