The red water-willow (Pachystachys coccinea) is an ornamental tropical plant that grows in humid undergrowth-type environments. This evergreen shrub was first observed and described in French Guiana in 1775 by the French botanist and explorer Jean-Baptiste Christophe Fusée-Aublet (1723-1778). It bears red flowers in long spikes at the end of its simple, cylindrical, upright stems. Each of the flowers in the form of a tubular corolla emerges from the axil of a small oval leaf. The scarlet flowers are usually opposite two to two, sometimes four to four.