Biological flora of the British Isles: Ruscus aculeatus

Abstract

Summary: This account presents information on all aspects of the biology of Ruscus aculeatus L. (Butcher's broom) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of the British Isles: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history and conservation. Ruscus aculeatus is a multistemmed monocotyledonous shrub with leaves functionally replaced by cladodes and photosynthetic stems. It is native to southern England primarily in dry shaded woodland and hedgerows (but widely planted elsewhere) often, but not exclusively, on base-rich soil. It is rarely abundant in any habitat, usually forming widely spread discrete clumps. Ruscus aculeatus is remarkably shade tolerant and drought resistant with low water conductance and transpiration, and water storage in the cladodes. Yet unusually for a drought-tolerant stem-photosynthetic plant, it prefers shady environments. The flowers have few if any pollinating mechanisms, low seed production and fruit/seed dispersal are largely ineffective, which may be a relict of its evolution in a tropical Tertiary climate. Population survival primarily depends upon vegetative spread from stout rhizomes, aided by the plant's general unpalatability. Over-collecting for medicinal steroidal saponins has caused some population declines, particularly in eastern Europe, but it is otherwise facing few conservation problems. © 2014 British Ecological Society.