The Cyperaceae

Like the Poaceae, flowers in the Cyperaceae (the sedges) have no perianth and occur in spikelets. Structurally, however, the spikelets differ from those of the Poaceae.

• In the Cyperaceae there flowers are subtended by a single bract, not sandwiched between a palea and a lemma.
• In the Cyperaceae, there are no sterile bracts (glumes) at the base of the spikelet, as there are in the Poaceae.

The most easily identifiable difference between the Poaceae and Cyperaceae, however, is that the stems of the Poaceae are round in cross-section, whereas the stems of the Cyperaceae are triangular in cross-section. (People remember this by remembering that "sedges have edges".) Illustration "C" in the image below showes a cross-section of stem "D".