Carex riparia, the greater pond sedge, is a species of sedge found across Europe and Asia. It grows in a variety of wet habitats, and can be a dominant species in some swamps. It is Britain's largest Carex, growing up to 130 cm (4 ft 3 in) tall, with glaucous leaves up to 160 cm (5 ft 3 in) long. It hybridises with a number of other Carex species, including the closely related Carex acutiformis – the lesser pond sedge. A variegatedcultivar is grown as an ornamental grass.
The leaves of C. riparia are up to 160 centimetres (63 in) long by 6–20 millimetres (0.24–0.79 in) wide, glaucous, and narrowing at the tip to a trigonous point.[3] The stems are 60–130 cm (24–51 in) tall, rough, and sharply triangular in section,[3] making C. riparia Britain's largest species of Carex.[4] They bear 1–5 female spikes, each nearly cylindrical and generally overlapping with the next, and 3–6 more densely arranged male spikes.[3] Each female spike is 3–10 cm (1.2–3.9 in) long, often with some male flowers at the tip, while male spikes are 2–6 cm (0.8–2.4 in) long.[3] The fruits of C. riparia are utricles, 5–8 mm (0.2–0.3 in) long, with an inflated ovoid shape. They taper to a distinct, bifid beak, which bears three stigmas.[3]
Carex riparia is known to hybridise with a number of other sedge species, including Carex acutiformis (forming Carex × sooi), C. lasiocarpa (forming C. × evoluta), C. rostrata (forming C. × beckmanniana), C. vesicaria (forming C. × csomadensis), C. elata and C. flacca.[3]
Horticulture
Carex riparia, particularly the cultivar 'Variegata', is used as an ornamental grass in gardens with wet soils.[5]
Notes
^Many North American sources erroneously attribute the species to M. A. Curtis.
^M. J. Y. Foley; M. S. Porter (2002). "Carex riparia". In C. D. Preston; D. A. Pearman; T. D. Dines (eds.). New Atlas of the British and Irish Flora. Oxford University Press. p. 722. ISBN978-0-19-851067-3.