Pleioblastus is an East Asian genus of monopodial bamboos belonging to the grass family Poaceae, order Poales. Described by the Japanese botanist Takenoshin Nakai, the genus contains approximately 30 species native primarily to China and Japan, with populations naturalized in Korea, parts of Europe, New Zealand, and the Western Hemisphere.
Members of Pleioblastus are running bamboos that spread by vigorous underground rhizomes (leptomorph rhizome system) which extend just beneath the soil surface and produce new culms at the nodes. This growth habit makes the genus highly useful for ground cover and erosion control, but it also means that uncontained plants can spread aggressively into surrounding areas. Culm heights range from low, dwarf species only a few centimetres tall to taller species reaching several metres.
The genus includes several widely cultivated ornamental species prized for their variegated foliage. Pleioblastus variegatus, with green and cream striped leaves, and P. viridistriatus, with green and gold striped leaves, have both received the Royal Horticultural Society's Award of Garden Merit. Other commonly grown species include P. simonii and P. gramineus, valued for their graceful, arching habit.
Taxonomically, Pleioblastus sits within the tribe Arundinarieae (temperate bamboos). Genetic research has raised questions about the genus's boundaries, suggesting it may be more naturally grouped within the broader genus Arundinaria. Numerous species formerly placed in Pleioblastus have been transferred to related genera including Pseudosasa, Sasaella, Sinobambusa, and Yushania.
Etymology
The genus name Pleioblastus derives from Greek: pleio- meaning "many" and blastos meaning "bud" or "shoot," referring to the many buds or shoots produced along the rhizomes. The genus was described by the Japanese botanist Takenoshin Nakai.
Distribution
Pleioblastus species are native to China and Japan, where they grow in forest understories, open hillsides, and disturbed ground. The genus has become naturalized in scattered locations in Korea, parts of Europe, New Zealand, and the Western Hemisphere, often as a result of garden escapes.
Cultivation
Several Pleioblastus species are cultivated as ornamental ground-cover plants, particularly for their variegated foliage. They thrive in moist, well-drained soils in full sun to partial shade. Because they spread by leptomorph (running) rhizomes, root barriers are recommended to prevent unwanted spread. Cutting plants back hard in late winter or early spring encourages fresh, brightly coloured foliage the following season. P. variegatus and P. viridistriatus are among the most widely grown and hold the RHS Award of Garden Merit.
Taxonomy Notes
Pleioblastus is placed in the tribe Arundinarieae within the grass family Poaceae. Molecular phylogenetic studies have indicated that the genus as traditionally circumscribed may be polyphyletic, with affinities to Arundinaria. Many species formerly assigned to Pleioblastus have been reclassified into related genera such as Acidosasa, Pseudosasa, Sasaella, Sinobambusa, and Yushania. The authorship of the genus is attributed to Takenoshin Nakai.
