10 ELODIACEAE 



b. Leaf-blades entire, rarely!cordate. 

 Filaments slender : leaf -blades seemingly pinnately veined. 



4. 5. rigida. 

 Filaments dilated : leaf-blades with veins distinct to the base. 



5. 5. graminea. 

 B. Pedicels of the pistillate flowers stout, reflexed at maturity. 



6. 5. subulata. 



1. Sagittaiia longirostra (Micbeli) J. G. Stnith. Long-beakbd 

 Arrow-head. (Man. p. 57 ; I. V.f. 1^3.) In swamps and along ponds. 

 N.J. and Pa. to Ala. — Pennsylvania: Lancaster; Delaware. 



2. Sagittaria Slngelmannlana J. G. Smith. Engelmann's Arrow- 

 head. (Man. p. 57 ; I. V.f. 1^4.) In shallow water, Mass. to Pa. and 

 Del. — Pennsylvania : Monroe, Tobyhanna ; Northampton ; Luzernb ; 

 Philadelphia. 



3. Sagittaiia latifolia Willd. Broad-leaved Arrow-head. (Man. 

 p. 57 ; I. F.y. 795. ) In low grounds and shallow water, nearly through- 

 out N. A. — Pennsylvania: Monroe; Northampton; Delaware; 

 Chester ; Lancaster ; Huntingdon ; ^''ranklin ; Erie ; Alle- 

 gheny. Common. 



3a. S. latifolia pubescens (Muhl.) J. G. Smith. (Man. p. 57.) — 

 Northampton, Seidersville. 



4. Sagittaria rigida Pursh. Sessile-fruiting Arrow-head. (Man. 

 p. 58 ; I. F.y. 201.) In shallow water and swamps, Quebec to Minn., N. 

 J., Tenn. andNeb. — Pennsylvania: Northampton; Bucks; Philadel- 

 phia ; Lancaster ; Dauphin, Harrisburg ; Bradford. 



5. Sagittaria graminea Michx. Grass-leaved Sagittaria. (Man. 

 p. 59 ; I. F.y. 204..) In shallow water or mud, Newf. to S. Dak., Fla. and 

 ts.-x..— Pennsylvania : Pike, Twelve Mile Pond ; Northampton ; Del- 

 aware ; Berks ; Erie. 



6. Sagittaria subulata (L.) Buchenau. Subulate Sagittaria. 

 (Man. p. 59; L F. /. 206.) In tidewater mud, N. Y. to Pa., Fla. and 

 Ala. — Pennsylvania : Philadelphia ; Delaware. 



6a. S. subulata graclUima (S. Wats.) J. G. Smith. (Man. p. 59.) — 

 Bucks, Bristol. 



Order 4. HYDEOCHARITALES. 

 Family i. ELODIACEAE Dumort. Tapb-Grass Family. 

 Staminate flowers with 9 stamens. i. Philotria. 



Staminate flowers with 1-3 stamens. 2. Vallisneria. 



1. PHILOTRIA Raf. 

 Leaf-blades oblong, elliptic or ovate-oblong. i. />. Canadensis. 



Leaf-blades narrowly linear. i,. /> angustifoUa. 



1. Philotria Canadensis (Michx.) Britten. WaTBR-weed. Ditch- 

 moSS. (Man. p. 60.) In ponds and streams, nearly throughout N. A. 

 — Pennsylvania: Northampton; Bucks; Philadelphia; Dela- 

 ware ; Chester ; Lancaster ; Lycoming ; Huntingdon ; Erie. 



