In the early autumn the roadside ditches and woodland streamsides often show spikes of a bright blue flower a deep, almost ultramarine blue marked with while on the three-parted lip. This is the great blue lobelia.
Lobelia siphilitica L.
July - September Ditches, streams.
Autumn somehow is the fitting time for blue flowers such as these. Now the sky becomes a deeper blue. There is a haze on the hills; there are flocks of bluebirds flying. The lobelia is another expression of that magnificent autumnall color.
Although the blossom is well suited to garden use, where truly blue flowers are scarce and in demand, the wild blue lobelia seldom is used in American gardens. But as early as 1665, seeds of this plant, together with other American rarities which were new to English eyes, were sent from the colony of Virginia to be grown in England. Here the flower was highly prized and many hybrids were produced from it. Across the world from its native land, the lobelia became a favorite garden flower.
But lobelias have been known still longer as medicinal plants. They contain in their juices a poison whose effeet is somewhat like that of nicotine when taken internally in large doses. It affects the respiratory system, the heart, and the blood pressure. Nevertheless, the lobelia's poison when administered in proper doses as a medicine is used to relieve asthma, bronchitis, and certain respiratory diseases.
Cardinal flower (Lobelia cardinalis), a bright scarlet lobelia, is a native of swamps and wet places, of the edges of drainage ditches which it margins with spikes of dazzling color, or of wet meadows where it grows with drifts of white and blue Eupatorium, marsh grasses, and golden rods.