284 



MONOCOTYLODENOUS. 



5 C AuTUMNALis. Stem terete. Spikes slender, terminal, digitate, usual- 

 ly by threes. Involucre 2-Ieaved, as long as the umbel- Glumes purple. 



%■ July — Aug. On margins of ponds. 



6 C CoMPRESsus. Stem triquetrous, naked. Zeares linear-lanceolate. — 

 Flowers in compound umbels; spikelets many flowered, nearly capitate. 

 Glumes acuminate, \vi;h white margins. 



11- Aug. — Sept. Sandy pastures. 3-8 in. 



7 C Vegetits. Stem slender, nearly terete. Leaves linear lanceolate, 

 channeled, finely serrulate near the summit. Flowers in compound um- 

 bels. S/)/AteZe/s in globose heads, /nvo/ucre 4-leaved. Glumes o\ ale. 



% June— Sept. Ponds and ditches. 2-3 ft. 



8 C ViRENS. Stem triquetruous. Leaves linear-lanceolate, 2-3 feet long. 

 Umbels compound ; spikelets in compact heads, many flowered. Involucre 

 long. Flowers monandrous. 



%. May — Oct. Rich swamps, common. 



9 C Mariscoides. Stem erect, glabrous, naked. Leaves channeled, ser* 

 rala'e. k'^jx/ces in globose heads, terminal. //iroZucre 3-leaved, long. Glumes 

 compressed. 



Sandv soils. 1 foot. 



Stem nearly terete, shining. Leaves linear, sheathing 

 Umbels compound; spikelets crowded, lanceolate. 

 Wet soils. 8-12 in. 



Leaves 3-angled. Vmlels 



Umbels 



% June— Sept. 



10 C Flavescens. 

 the stem at the base. 



% July-Oct. 



11 C Gracilis. ^S/era slender, acutely angled, 

 compound ; spikelets linear-lanceolate. 



ig) Sept. — Oct. Damp soils. 10-12 in. 



12 C Kydra. Stem obtusely angled. Leaves radicle, recurved, 

 simple and compound ; sj)ikelets linear. Involucre 2-3-leaved. 



%. Through the summer. Sea coast. 3-8 in. 



13 C Repen?. Stem S-angled, with the sides concave. Leaves glabrous, 

 recurved. Umbels usuallv simple. Involucre 3-4-leaved. Spikes crowded. 



% July— Sept. Infields. 12-18 in. 



14 C Tenuiflorus. Stem leafy, nearly terete. Leaves channeled, serru- 

 late. Sjnkes corymbose ; spikelets linear. Involucre many leaved, with the 

 two exterior very long. FUwers frequently diandrous. 



13 C Strigosus Stem 3-angled. Leaves long, minutely serrate. Spihes 

 oblong; spikelets subulaie. Inv(,lucre longer than the umbel. 

 % August— Oct. Wet places. 2-3 ft. 



16 C Tetragoxus. Stem naked, angled. Leaves channeled, serrulate. 

 Umbels many rayed. Spikes 3-5 flowered. 



% 2-3 ft. 



17 C Flavicomis. S<e»j obtusely angled. ieaue-sHnear-lanceoIate, slight- 

 ly serrulate near the summit. Umbels compound. Involucre long. Spikes 

 expanding, 10-12-fljwered. 



% May— Sept; Rich soils. 1-2 ft 



18 C Speciosus. Stem erect, angled. Leaves channeled serrulate. Spikes 

 in corymbs; spikelets subulate, 6-8 flowered, distichous. Involucre many 

 leaved, long. Involucels longer than the partial umbels ; common peduncles 

 sheathed at the base. 



%. August— Oct. Wet places. 2-4 fi. 



19 C Enslenii. Sle7n 3-angled. Leaves linear, scabrous along the midrib 

 and mariiins. Spikes corymbose, branching at the base ; spikelets numerous, 

 hnear, crowded, brown. Involucre 8-!eaved, exterior one longest. 



% August— Sept. In wet places. 1-2 ft. 



Genus II DULICHIUM. 



Spikes somewhat racemose, axillary. Spikelets linear-lau- 



