Great Blue Lobelia, Blue Cardinal Flower, Big Blue Lobelia, Great Lobelia

Lobelia siphilitica

Physical Characteristics

Lobelia siphilitica is a PERENNIAL growing to 1 m (3ft 3in) by 0.3 m (1ft) at a medium rate. See above for USDA hardiness. It is hardy to UK zone 5. It is in flower from August to September. The species is hermaphrodite (has both male and female organs). Suitable for: light (sandy), medium (loamy) and heavy (clay) soils. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It can grow in semi-shade (light woodland) or no shade. It prefers moist or wet soil.

Distribution

Eastern N. America - Maine to S. Dakota, south to Texas and Missouri.

Habitats

Bog Garden;

Edible Uses

None known

Medicinal Uses

Analgesic Cathartic Diaphoretic Dysentery Emetic Homeopathy Poultice VD The root is cathartic, diaphoretic and emetic[4, 46, 103]. It is used in the treatment of dropsy, diarrhoea, stomach complaints, syphilis and dysentery[4, 257]. A poultice of the root has been applied to sores that are hard to heal[257]. The leaves are analgesic and febrifuge[257]. An infusion has been used in the treatment of colds and fevers[257]. A poultice of the crushed leaves has been applied to the head to relieve the pain of headaches[257]. At one time in N. America the root of this plant was believed to be effective in the treatment of VD[103, 222]. When used in Europe, however, it was found to be ineffective[213]. This might have been because the N. American Indians used the fresh root (which still contained the volatile oils) and also used it in conjunction with Podophyllum peltatum and Prunus virginiana, and then dusted the ulcers with the bark of Ceanothus americanus[213]. It was believed by some native North American Indian tribes that if the finely ground roots were secretly added to the food of an arguing couple then this would avert a divorce and they would love each other again[213]. A homeopathic remedy is made from the roots[4].

Known Hazards

The plant is potentially poisonous[222]. It contains the alkaloid lobeline which has a similar effect upon the nervous system as nicotine[274].