Carex Genus sedges Cyperaceae (Flora of North America Editorial Committee 1993+).

Carex radiata_Perigynium dorsal face with scale.Creative Commons.Cyperaceae.eMonocot.org

Carex radiata_Perigynium dorsal face with scale (L.).Creative Commons.Cyperaceae.eMonocot.org (Accessed 5/2014).

Carex are grass-like plants (see Cyperaceae) all have C3 photosynthesis (Bryson and Carter 1977). Stems often 3-sided, usually solid. 

Leaves alternate, grass-like. 

carex-amphibol-bob-klips-bobklips-com_website

Carex amphibola.carex flowers.Bob Klips.bobklips.com_website

Flowers papery, male and female flowers are separate (monoecious) usually on the same inflorescence, the female flower is composed of a sac-like perigynium, without petals or sepals, the top of the perigynium is open and is often extended into a beak that may bear two tooth-like points at its tip; there is also a scale-like bract at the base of each perigynium; the male flowers consist of 3 stamens above a scale-like bract, Male flowers are often in a separate spike at the top of the inflorescence, or sometimes clustered at the top or base of the female flower spikes. 

Carex communis.Arthur Haines.New England Wild Flower Society.gobotany.newenglandwild.org (Accessed 5/2014).

Carex communis.Arthur Haines.New England Wild Flower Society.gobotany.newenglandwild.org (Accessed 5/2014).

Fruit dry, enclosed in enlarged perigynium; a 1-seeded achene.