GBJMINEAE. 39 



13. CENCHEUS L. Hedgehog or Bur-grass. 



Involucres less than 5 mm. broad. 1. C. tribuloides. 



Involucres more than 5 mm. broad. 2. C. inacrocephalus. 



1. Cenchrus tribuloides L. M. p. 90. Sandy shores and waste places. 



Summer. 

 Philadelphia— CP.). ^moAs — Near Delav^-are River (Fr.). Delaware— 

 Swarthmore (Pr.), Concord (W. Tr.), Tinicum (B. Sm.). Chester— (F.). 

 Lancaster— (F.) Lehigh— AWentown (Kv.). Northampton — {F.). Dau- 

 phin — (P.). 

 Netv Jersey — Common. 

 New Castle— l<le-w Castle and Collins, common. 



2. Cenchrus macrocephauus (Doell.) Scribn. M. p. 1042. Along the sea- 



shore. Summer. 

 Cape May — Stone Harbor (St.). 



14. ZIZANIA L. 



1. ZiZANiA AQUATICA L. Wild Eice, Seed, Indian Bice. M. p. 91. Swamps. 

 Summer. 



15. HOMALOCENCHRUS Mieg. 



Spikelets 2.5-3 mm. long; panicle branches usually rigid. 1. H, Firginicus. 

 Spikelets 4-5 mm. long ; panicle branches generally lax, 2. H. oryzoides. 



1. HOMALOCENCHRUS ViRGiNicus (Willd.) Britton. White Grass. M. p. 91. 



Wet woods or swamps. Summer. 



Philadelphia— ByheTTj, Mart. (B. C), Wissahickon (VP.). Bucks — 

 Sellersville (Fr.). Delaware— Media (B. Sm.), Concord (W. Tr.). Ches- 

 ter— (F.). Lancaster — (P.). Northampton— Easton, Porter (B. C). 



Camden— Merchantville (Sts.). Gloucester— Miekleton (He.), Swedes- 

 boro (Li.). (SaZem — Woodstown (Te.). Hunterdon— Clmton (Te.). 



New Castle — Common. 



2. HOMALOCENCHRUS ORYZoiDEs (L.) Poll. Blce Cut-grass. M. p. 91. "Very 



wet places. Summer. 



16. PHALARIS L. 



Outer scales not winged. 1. P. arundinacea. 



Outer scales broadly winged. 2. P. Canariensis. 



1. Phalaris ARUNDINACEA L. Seed Canary-grass. M. p. 92. Wet grounds. 



Summer. 



2. Phalaris Canariensis L. Canary-grass. M. p. 92. Waste places. 



Summer. 



17. ANTHOXANTHUM L. 



1. ANTHOXANTHUM ODORATUM L. Siucet Vernal Grass. M, p. 92. Meadows 

 and pastures. Early summer. 



18. SA VAST ANA L. 

 1. Savastana odorata (L.) Scribn. Holy-grass. M. p. 93. Moist mead- 

 ows near the coast. Summer. 



