Physostegia purpurea

About this plant

Physostegia purpurea, the Eastern false dragonhead, is an unusual North American swamp plant that forms a low submerged rosette of about 10 cm in aquariums. Its natural range lies along the coastal plain of the southeastern United States, where it grows in open acidic wetlands. The underwater form is very slow but easy to maintain in medium to strong light with a nutrient-rich substrate. Carbon dioxide addition around 20 to 40 mg/L is recommended rather than essential. The species is not a tropical heat lover: it tolerates roughly 4 to 25 °C, grows best near 22 to 24 °C and should not be kept above 25 °C for long periods. Propagation is unusually flexible and includes runners, cuttings, division and adventitious daughter plants. In emersed culture it changes dramatically, producing tall flowering stems with red-violet blooms. Its compact submerged habit suits foreground and midground groups, especially in North American or cool-water planted aquariums.