New England southward.
Flowers; axillary; growing singly or in clusters along the flower-stalk. Calyx: small; five-toothed. Corolla; tubular; two-lipped, the upper lip two-cleft; the lower one three-cleft with the middle lobe much larger than the others Stamens: four; the anther-cells approach and form a little cross. Pistil: one; style, two-lobed. Leaves: opposite; on petioles; roundish kidney-shaped; smooth. Stem: creeping; trailing.
This is the little plant that the English love so dearly and which blooms abundantly in the pasturage every springtime. We have hardly the same fondness for it here and rather resent the calm manner in which it has taken possession of the soil, especially where it is most distasteful to cattle. It is allied to our catnep, also a European plant, and was formerly much used as a medicine.
We are frequently amused to watch the growth and self satisfaction of many European plants that establish themselves in this country and sometimes exterminate those native to the soil. What advantage have they, we naturally ask, that makes them triumphant in the survival of the fittest? Very probably it is because they leave their destroying insects on the other side of the water. If this is so we cannot but sympathise with them in their attempt to flee from persecution.