1. Achene ribbed (like a pumpkin), the base concave, pitted, or glandular between the basal corners...2

1. Achene smooth, warty, or reticulate but not ribbed, the base free of pits or glands...3

2. Achene base concave but not glandular...S. baldwinii

2. Achene base with 2 glandular pits on each face...S. georgiana

3. Achene surface smooth...6

3. Achene surface pitted, reticulate, or warty...4

4. Achene warty; hypogynium absent...S. verticillata

4. Achene reticulate; hypogynium present...5

5. Hypogynium not lobed or scarcely lobed, the hypogynium warty...S. ciliata

5. Hypogynium strongly lobed, the hypogynium smooth..S. reticularis

6. Leaves to 1 cm wide or broader...S. lacustris

6. Leaves to 6 mm wide...7

7. Leaves 3-6 mm wide; culms 40-100 cm tall; spikelets 3-9 mm long, in terminal and lateral ascending fascicles...S. triglomerata (Achene a little 3-angled)

7. Leaves 1.5-4 mm wide; culms 15-65 cm tall; spikelets 4-5 mm long, in nodding clusters...S. distans (often mis-named S. hirtella)


Species notes:

S. baldwinii: Hypogynium absent or a small triangular plate. Achene ribbed and strongly mucronate, concave between the basal corners, 3-4 mm long (Ribbed also in S. georgiana, but S. georgiana with two pits on the faces of the achene bases)

S. ciliata: Reticulate. Hypogynium unlobed or scarcely lobed, tuberculate

S. georgiana: Skinny little Scleria, grassy; no hypogynium or this an obscure triangular plate; achene 2-3 mm (3-4 mm in similar S. baldwinii), ribbed; base of achene with two pits on each face (ribbed also in S. baldwinii, which has no pits on the basal faces of the achene)

S. reticularis: Achene reticulate. Hypogynium strongly lobed, smooth

S. triglomerata: Plants large for a local Scleria, the leaves 3-6 mm wide. Achene smooth; achene obscurely 3-angled.

S. verticillata: No hypogynium. Achene warty.