MONOCOTYLEDONS. — CYPERACE.^. Scirpus. 1/3 



2. SCHCENUS. 

 Scales imbricating the spike on all sides, the exterior ones smaller, 

 without flowers. Achenium naked or with a few bristles at 

 its base. 



* Culms leafy. 



1. Sch. alius f culm triangular, leaves linear-setaceous, flowers 

 terminal subcorymbose as long as the involucrum.p. 16. — Bogs. 



** Culms naked. 



2. Sch. nigricans, culm rounded, spikelets of flowers collected 

 into an ovate cluster, involucrum of two leaves, the exterior 

 one longer than the flowers, p. 16. — Bogs. 



3. Sch. compressus, culm roundish, spike distichous shorter 

 than the monophyllous involucrum, spikelets many-flowered, 

 leaves plane, p. 16. — Bogs, rare. 



4. Sch. rufuSj culm rounded, spike distichous longer than the 

 involucrum, spikelets few-flowered, leaves setaceous channelled. 

 p. 17. — f^et moors. 



3. SCIRPUS. 

 Scales imbricating the spike on all sides, one or two of the outer 

 ones occasionally without flowers. Achenium naked, or with 

 bristles at its base. 



* Spike solitary, 

 ■f Culms simple. 



1. Sc. ccBSpitosns, culm rounded, sheath terminating in the ru- 

 diments of leaves, two outer scales as long as the spil;e invo- 

 lucrate, stigmas 3. p. 17. — Moors. 



2. Sc. paucijinrus, culm rounded, sheaths leafless, spike ovate 

 naked, scales obtuse nearly equal, two outer ones the largest 

 but shorter than the spike, stigmas 3. p. 17. — Mountains. 



3. Sc. palustris, culm rounded, sheaths at the base leafless, 

 spike oblongo-ovate naked, scales nearly equal in size, stigmas 

 2. p. 18. — Marshes. 



4. Sc. acicularis, culm compressed grooved, sheaths leafless, 

 spike ovate acute naked .(no involucrum), scales acuminate, 

 stigmas 3, fruit without bristles, p. 18. — Marshes, 



ft Culms branched. 



5. Sc. Jluitans, culm rounded leafy flaccid, spikes ovate naked 

 (no involucrum), scales rather obtuse, stigmas 2, fiuit desti- 

 tute of bristles, p. 18. — Ditches. 



** Spikelets many. 

 f Culms rounded. 



6. Sc. lacustris, upper sheaths leafy, cyme terminal twice com- 

 pound, involucrum 2-leaved. p. 18. — Sides of lakes. 



7. Sc. setnceus, culms setaceous rounded or very slightly com- 



