And so Dr M has at last arrived at the Cyperaceae, not that he has been avoiding it, Dr M finds the Cyperaceae a very fascinating family indeed. It is just that Dr M has been rather preoccupied with the Poaceae recently. This post redresses the balance ever so slightly and in the future Dr M will post more and more on sedges and their relatives!
Cyperaceae is a rather diverse family and in Britain although Carex (the true sedges) is the most familiar genus, it is one of a total of fifteen genera!
Blysmus, Bolboschoenus, Carex, Cladium, Cyperus, Eleocharis, Eleogiton, Eriophorum, Isolepis, Kobresia, Rhynchospora, Schoenoplectus, Schoenus, Scirpoides, Scirpus, Trichophorum
Images of those emboldened are shown below.
The Cyperaceae in brief:
- Globally around 5,500 species in over 100 genera
- Herbaceous usually perennial, rhizomatous and tufted or spreading
- Monocots, leaves linear with parallel veins and arranged in 3 ranks
- “Sedges have edges” and so the leaves have distinct minutely serrated edges and the inflorescence stems are usually 3-sided (trigonous) and solid, quite unlike grasses or rushes
- Ligule are present and adnate (fused to the leaf blade, unlike the free ligules of grasses)
- There are no stipules or auricles
- Flowers are much reduced (even more so than grasses) each flower is subtended by just one scale or bract called a glume
- There are 1-many flowers grouped in spikelets which may be terminal, solitary or in terminal spikes, racemes or panicles
- Flowers may be bisexual or unisexual and each flower has 2 or 3 stamens and/or 2 or 3 stigmas
- There is no perianth or the perianth may be represented by bristles, these may elongate in fruit (as in the Cotton Grasses)
- The fruit of Cyperaceae is a nut, in the true sedges (Carex spp) the nut is enveloped by a flask-shaped structure called the utricle (very important for ID)
- Most species grow in wet places such as swamps and bogs and also in grasslands and woodlands, the smaller sedges often associated with poorer soils
Examples of Cyperaceae:
Click on the images for a better view
The featured image is of Eriophorum angustifolium at Malham Tarn NNR in West Yorkshire