Digitaria sanguinalis Hairy Finger-grass

An annual grass species which is most common in Britain as a weed of bulb fields and as a bird seed alien. It is a native of the Mediterranean and other parts of southern Europe which has been known wild in Britain since the 18th Century and is found throughout the world as a neophyte. It is probably spreading in Britain, particularly as a weed in gardens but also in waste places and street habitats in urban areas. The distinctive, long, thin finger-like inflorescences make it conspicuous when it is in flower. There have been few records in West Glamorgan but it may become more common in future. A number of other Digitaria species have been recorded in Britain, such as Digitaria ischaemum and Digitaria ciliaris which could be a source of confusion. Like Cockspur (Echinochloa crus-galli) and Bristle-grasses (Setaria spp.) which occur in similar places, Digitaria species exhibit C4 photosynthesis where the primary carboxylation event in photosynthesis, which results in the formation of a C4 carboxylic acid, occurs outside the chloroplast. Transfer and decarboxylation of the C4 compound into the chloroplast then enriches the chloroplast with carbon dioxide and this contributes to the high water use efficiency of these species enabling them to compete successfully in warm, dry climates.

Neophyte