=Flax Dodder.= _Cuscuta Epilinum_ Weihe. Stems very slender, yellow or red, a parasitic vine; seeds dull, yellowish to dark brown, minutely pitted, nearly spherical, oval, ovoid, 1-1.5 mm. long. Introduced from Europe.
=Clover Dodder.= _Cuscuta Epithymum_ Murr. Stems very slender, a parasitic vine; seeds oval to spherical, dull, pitted, color yellowish, light to dark brown, light green to purple, about 2 mm. long. Introduced from Europe. Occasionally found on red clover.
=Gronovius Dodder.= _Cuscuta Gronovii_ Willd. Seed light to dark brown, surface minutely granular, free from gloss, a few spherical, most of them indented as they dry or variously angled where they crowded against each other in the pod, 1.5-1.7 mm. in diameter. Species of dodder are difficult to distinguish one from the other. This is common on low land, where it draws nourishment from a great variety of plants, such as willows, balsams, nettles.
=Spanish Dodder.= _Cuscuta planiflora_ Tenore. Color light to dark pink, purple buff, olive green; surface well roughened, almost reticulated, in shape flattened on one side, ovoid, oval angled, indented in great variety, 0.7-1.2 mm. long.
=Hound's Tongue.= _Cynoglossum officinale_ L. Flowers reddish purple; ovary brown deeply 4-lobed separating into four achenes, 5-7 mm. long, flattened, broadly ovate or circular, excepting a slight extension at one end, lower side having an ovate scar, nearly half as long as the achenes, all the rest of the surface clothed with straight, stiff, cap-shaped hairs, bearded on all sides. Introduced from Europe. Very objectionable in pastures.
=Stick-Seed. Burr Seed.= _Lappula echinata_ Gilibert. _Lappula Lappula_ (L.) Karst. Flowers blue, ovary deeply 4-lobed separating into four warty achenes, each one brown, about 2.5 mm. long, slightly flattened, ovate with wedge-shaped apex; the upper side bearing a few stiff straight, diverging cap-shaped hairs, bearded on all sides; lower side destitute of hairs, bearing a straight ridge from the point to the middle of the large end. Introduced from Europe. Very objectionable in pastures.
=Wild Comfrey.= _Lappula Virginiana_ (L.) Greene. Flowers blue; ovary deeply 4-lobed separating into four brown achenes, about 3 mm. long, flattened on upper side, broadly ovate, the apex wedge-shaped, the upper side clothed with stiff straight cap-shaped hairs, bearded on all sides; lower side a low 4-sided cone, nearly smooth with a concave triangular scar. Native to rich woodlands.