Lobelia puberula aka Purple Dewdrop

Lobelia puberula has two common names: downy lobelia and blue lobelia. It is a perennial wildflower, which means it lives for years. It belongs to Campanulaceae, the bellflower family. It is native to the eastern and south-central United States. It grows in bogs, swamps, meadows, and woods. It also grows in prairies and open fields. This blue-flowered lobelia grows widely in the Southeast.

Plants grow upright to 2–4 feet (0.6–1.2 metres) tall. They grow at a moderate pace. Each plant may live a short time but makes many seeds. The round, hairy stems are green, at times with purple tones. Soft green leaves grow in turn along each stem. These sessile leaves have no leaf stalk. They range from oval to lance-shaped, with small, uneven edge teeth. Leaves may have hairs, most clear on their lower sides. Leaves at the base form a ring, or rosette. This often stays green through winter.

Flowers open from August to October on spikes at stem tips. Blooms may grow along just one side of each spike. Each flower is blue to purple-blue with a white centre. Two lobes make up the top lip; three make the lower. Bees pollinate the blooms, which also draw butterflies and hummingbirds. Round seed cases, called capsules, follow the flowers. They hold many seeds and ripen in fall. These seeds can grow new plants.

Grow downy lobelia in full sun or part shade. It likes moist, acidic soil that drains well. It also grows in neutral soil and handles clay, loam, or sand. Plants cope with brief wet spells and times of dry soil. Its reported hardiness spans USDA zones 4–9. Use it in borders, meadows, woods, or small groups. It also suits native, cottage, rain, and pollinator gardens. Asters and goldenrods suit its late blooms as companion plants. Grow new plants from seed or by division, splitting a plant.

Slugs and snails may chew the leaves. Aphids and spider mites can cause problems too. Diseases may include gray mold and root or stem rot. Reports differ on how well it resists deer. Deer may still browse it. The plant is poisonous to people, cats, and dogs. Leaves, flowers, fruits, and seeds all contain poison. So do roots, stems, and sap. Its poison rating is low, but symptoms can be severe. These include vomiting, diarrhea, and weakness. Convulsions and coma can also occur. Its toxins include lobeline, lobelamine, and a volatile oil. It is not a food plant. There are no reports of contact dermatitis, a skin rash from touch.