Pachystachys is a genus of flowering plants in the family Acanthaceae, placed within the order Lamiales. It comprises roughly 12 to 18 accepted species of evergreen perennials and shrubs native to tropical rainforests of the Caribbean and Central and South America. The genus is closely allied to Justicia and shares the same family with other well-known ornamentals such as Acanthus and Thunbergia.
Plants in this genus are recognizable by their prominent terminal spikes bearing tubular flowers subtended by brightly coloured, overlapping bracts that persist long after the individual flowers have faded. This striking inflorescence gives the genus its name: Pachystachys derives from the Greek words for "thick" and "spike," a direct reference to the dense, showy flower heads.
Among the best-known members are Pachystachys lutea (the golden shrimp plant or lollipop plant), widely grown for its bright yellow bracts and white flowers, and Pachystachys coccinea (the cardinal's guard), valued for its scarlet flower spikes. These species and P. spicata are the most commonly encountered in cultivation, grown as garden shrubs in subtropical climates where temperatures remain above 10 °C (50 °F), and as houseplants or under glass elsewhere.
Etymology
The genus name Pachystachys is derived from the Greek words pachys ("thick") and stachys ("spike"), referring to the dense, prominent terminal spikes that characterize the genus's inflorescences.
Distribution
Pachystachys species are native to tropical rainforests of the Caribbean and Central and South America. In cultivation, they can be grown outdoors in subtropical gardens where temperatures do not drop below 10 °C (50 °F), and as houseplants or under glass in cooler climates.
Cultivation
The cultivated species — principally P. lutea, P. coccinea, and P. spicata — can be grown outdoors in subtropical gardens where temperatures remain above 10 °C (50 °F). In temperate regions they are kept as houseplants or in heated glasshouses. They prefer bright, indirect light and consistently moist, well-drained soil.
