TRIANDRIA.— MONOGYNIA. 39 



IIAB. Borders of ponds. Aug. — Sept. 2J. A foot 

 high; leaves few, subulate; spikes turgid; seed 

 obovate ; bristles 4 — 5. 



13. S. lacustris: culm terete, attenuated above, naked ; 



panicle subterminal ; spikes peduncled, ovate. 

 HAB. Ponds and river marshes. June. If.. Culm 

 4 — 8 ft. high , sheathed at the base ; spike subpani- 

 tied ; glum, ovate, subpubescent ; seed obovate. 



14. S. acutus: culm terete, (not attenuated,) spotted ; 



peduncles numerous, sublateral ; spikes oblong ; 



glumes pubescent, mucronate. 

 HAB. Ponds and wet swamps. June — July. If. 



Culm 4 ft. high, with oblong brown spots ; panicle 



proliferous ; glum, dilated, carinate. 

 \h. S. atrovirens: culm triangular, leafy ; cyme termi- 

 nal, compound, proliferous ; involucrum 3-leaved ; 



spikes conglomerate, ovate, acute ; glumes ovate. 



mucronate, pubescent. 

 HAB. Wet meadows. June— July. If. Culm obtusely 



triang. 2 ft. high ; involuc. long ; .spikes dark green, 



in heads of 10 — 12. 



16. S. brunneus: culm leafy, obtusely triangular ; cyme 



decompound ; involucrum 3 — 4-leaved ; spike 

 round-ovate, clustered in about sixes ; glumes 

 ovate, obtuse. 

 HAB. In water. Aug.— Sept. If. Culm 2— 3ft. 

 high ; leaves long ; spike brow?i ; seed longer thai, 

 the bristles. 



17. S. tnacrostachyos : culm triquetrous, leafy ; corymb 



clustered ; involucrum about 3-leaved, very long ;. 

 spikes oblong ; glumes ovate. 3-cleft ; the middle 

 segment sububite and reflexed ; style 3-cleft. 

 HAB. In salt marshes and ditches. July — Aug. If. 

 Culm 3 — Aft. high ; spikes 6 — 10, very large. 



Style filiform, deciduous. Bristles much longer than 

 the seed. 



10. S. Eriophorum : culm obtusely triangular, le;m 

 pimicle decompound, proliferous, nodding ; spikes 

 all pedunculate ; bristles surrounding the seed 

 exserted. 

 HAB. Swamps. Aug. If. Culm 4—5 ft. high ; in- 



