The Manual of the Botany of the Northern United States Part 186

[+] 2. _Ovales._ Spikes tawny or dark, rather large, sometimes crowded; perigynium with a more or less thin or winged margin, which is mostly incurved at maturity, rendering the perigynium concave inside.--Sp.

125--132.

[+] 3. _Cyperoideae._ Spikes green, oblong, densely crowded into a short head subtended by two or three leafy bracts which are erect and prolonged from six inches to a foot; perigynium linear-lanceolate, scarcely margined.--Sp. 133.

Artificial Key.

Spike 1, staminate at top; scales of pistillate flowers leaf-like Sp. 93-95

Spike 1, scales not leaf-like.

Usually dicious, stigma 2 115-117

Stigmas 3.--

Perigynium densely hairy 84

Spike staminate at base; perigynia squarrose 21

Spike staminate at top.--

Globose; leaves broad 97

Perigynium nearly linear, beakless 96

Perigynium long, spindle-shaped 1

Spikes several or numerous, sessile, spicate or capitate; stigmas 2.

All in a globose or ovoid uninterrupted head.

All staminate above.--

Usually green at maturity 112, 114

Usually yellow or tawny or brown 98, 99, 104, 105

All staminate below.--

Leafy-bracteate 133

Not leafy-bracteate.--

Green 118-120

Usually tawny or brown 125-132

Some or all of the spikes distinct or the head interrupted.

Staminate and pistillate flowers variously disposed, some of the spikes often unis.e.xual.

Head large and long 108, C. arenaria

Head short or linear 124, 125

Spikes staminate above 100-114

Spikes staminate below 118-133

Spikes usually more or less pedicelled, the wholly or partially staminate spikes uppermost.

Terminal spike (rarely the 2 or 3 uppermost) staminate only at base.

Stigmas 2 34-38, 79

Stigmas 3; spikes erect,

Short and squarrose 20, 21

Not squarrose 22, 30, 32, 46, 47, 54, 79

Stigmas 3; spikes more or less drooping 31, 51-53, 55-57

Terminal spike or spikes staminate.

Stigmas 2.--

Spikes spreading or pendulous 34, 37, 40, 41

Spikes erect or nearly so 9-16, 34-41, 85-91, 79

Stigmas 3; spikes spreading or drooping.

Perigynium prominently 3-angled 68-74

Perigynium large, thin, much inflated 9-16

Perigynium firmer, not inflated.

Beakless 42-45

Beaked or prominently pointed.--

Teeth long, stiff and sharp 17-19

Teeth short and thin, or none 30, 31, 39, 48-53

Stigmas 3; spikes erect or ascending.