Arnica (Arnica Mollis) is a northern plant with large, delicate, pure yellow, daisy-like flowers. Its slightly hairy stem grows from 1 to 2 feet tall. The basal leaves are long-petioled but the stem ones are sessile and opposite, shallow-toothed. At the summit are one to nine flower heads on slender peduncles. About the central disc are 10 to 14 yellow rays, each with three notches in their ends. Found in Canada and the mountains of northern U. S.
Burdocks Arctium minus.
Burdock (Arctium Minus) (European) is a very common plant on waste ground, along roadsides and the edges of woods. The plant is often four feet or more high. The lower leaves are very large, often more than a foot in length, heart-shaped, deep green and finely veined above, greyish beneath because of the fine wool that covers the under surfaces. The upper leaves are smaller, more ovate in form and less densely woolly on the undersides. The flowerheads grow in clusters at the ends of the branches. The involucre is almost spherical, - composed of numerous bracts, each terminating in a sharp, hooked point. Tubular florets, only, are seated within this involucre; they are purple and white in color, and secrete an abundance of nectar, on which account they are frequented by honey bees.
We have seen how the Milkweed attaches to each of its seeds, a little parachute so it may fly away on the winds and found new colonies at a distance from the parent plants. We have also seen how the Beggar-tick and members of the Genus (Bidens) disperse their seeds by attaching them to the hair of animals or the clothing of man. The present species adopts the policy of the Beggar-ticks, but instead of single seeds, it attaches the whole bur-like head by means of its numerous little hooks. They cling tenaciously to everything they touch; doubtless most of my readers recall massing these burs together to make castles, funny men, animals, etc.
We have two species of this plant, - the present, and one slightly larger and with coarser leaves, (A. Lappa). Both of them are immigrants from across the water.
Canada Thistle. Cirsium arvense.
Canada Thistle (Cirsium Arvense) (European) is a small flowered, perennial species that has strayed across the ocean and became a pernicious weed. Individual plants are not themselves any more of a pest than are our native thistles but they have a dangerous, latent or potential power, in that they are far more prolific than our native species, due perhaps more to the number of the flowering heads than to any physical qualities of the plant.
The stem is rather slender, branching and grows from 1 to 3 feet in height. It grows from a perennial, creeping rootstalk that is, as farmers have discovered, very difficult to eradicate from the soil. It grows in extensive colonies and, unless strenuous efforts are made to destroy them, they very soon take possession of a field to the exclusion of almost everything else.
The leaves, that grow alternately and closely together on the stem, are long, lance-shaped, deeply cut into sharply-prickled lobes. Numerous flower heads, about one inch across, terminate the branches. When in full bloom, the florets vary in color from rose-purple to white; the involucre is almost globular and covered with over-lapping bracts, each with a tiny, sharp, out-turned point.
All the thistles yield an abundance of nectar and are frequented by bees and butterflies, by one of the latter so persistently that it has been named the Thistle Butterfly or Painted Lady (Pyrameis cardui); in fact this butterfly usually begins its career, as a caterpillar, on the thistle and lives chiefly upon its nectar and pollen through life.
Pasture Thistle. Cirsium pumilum,