Eleocharis parvula. Dwarf spikerush.

Life-form & Growth Form:  

Hemicryptophyte. Herbaceous perennial. Rhizomatous, with rhizome far-creeping. Can also spread via fragmentation.  

Flowering period: 

July and August. Seldom flowers.


In Northern Ireland restricted to tidal sandy estuarine mud. Saltmarshes, saltmarsh pool, tidal pans in brackish grazing marshes. Avoids strong saline substrates. Lowland. 


Natural erosion processes. Agricultural run-off. Being restricted to a single site within Northern Ireland puts E. parvula at great risk of regional extinction. River engineering works and/or major river pollution events could destroy the population. Relies largely on vegetative spread as flowering is sporadic. Climate change and rising sea level will also gradually cause the current distribution of this species to change. Cessation of grazing allowing taller vegetation. Dredging. 

Static distribution map:
Eleocharis parvula 10 km atlas 1000
Eleocharis parvula
For an interactive map follow this link to the BSBI webpage