categoryZGrasses Grasses List 

GREATER POND-SEDGE

Carex riparia

Sedge Club- & Spike-Rush Family [Cyperaceae]

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category
category8Grasses
 
status
statusZnative
 
flower
flower8brown
male
flower
flower8brown
female
petals
petalsZ0
 
type
typeZspiked
 
stem
stem8triangular
concave
sex
sexZmonoecious
 

31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone
Greater Pond-sedge has a stouter stem than Lesser Pond-weed. Also the male spikelets (the thinner ones at the top) are more numerous (at between 3 and 6) than those of Lesser Pond-weed and longer (2 to 6cm) with glumes 7 to 9mm long.

The female spikelets below them are both longer (3 to 10cm long) and stouter (10 to 12mm wide) with the lower female spikelets usually with long stalks and more tapering at their ends than are those of Lesser Pond-weed



31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone


31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone
The leaf-sheaths are also more translucent and paler than those of Lesser Pond-weed and moreover do not usually break up into thinner filaments.


31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone
The female glumes are 7 to 10mm long and more pronouncedly oblong and are sharply tapered to a long point than those of Lesser Pond-weed. The fruits are 5 to 8mm long, ovoidal, and bulging; first green then dark greyish-brown. The beak of the fruit gradually tapers to a long beak which is forked at the tip.


31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone


31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone


31st May 2005, Yarmouth, IoW. Photo: (CC by 2.0) Geoff Toone
Greater Pond-sedge has broader leaves (6 to 15mm wide as opposed to 7 to 10mm wide) than Lesser Pond-weed. The leaves are also more upright.


Hybridizes with :

  • Lesser Pond-Sedge (Carex acutiformis), but only very rarely, to produce Carex × sooi even though the two are often found together. Lesser Pond-sedge is found in a few sites in East and Central England as well as Glamorgan.
  • Bottle Sedge (Carex rostrata) to produce Carex × beckmanniana which was found in Orkney in 1992 and was still there in 2018.
  • Bladder Sedge (Carex vesicaria) to produce Carex × csomadensis which was found in County Wicklow, Southern England and Berwicks.

Like Lesser Pond-Sedge, Bottle Sedge, Glaucous Sedge, Starved Wood-sedge, Dotted Sedge, Sheathed Sedge and indubiatably several others - they have 3 styles (rather than 2).

It is native and grows in shallow water (as does Lesser Pond-Sedge) such as fen woods, reed swamps, beside ponds and rivers. The fruits are extant between June to September.


  Carex riparia  ⇐ Global Aspect ⇒ Cyperaceae  

Distribution
 family8Sedge Club- & Spike-Rush family8Cyperaceae
 BSBI maps
genus8Carex
Carex
(Sedge)

GREATER POND-SEDGE

Carex riparia

Sedge Club- & Spike-Rush Family [Cyperaceae]