144 MONOECIA— POLYANDRIA. Sagittaria. 



Knotted Pondweed. Petiv. H. Brit. t. 6./. 8. 



In ponds and ditches, much less common than the former. 



Near Cambridge. Ray. At Bungay, Suffolk, and Hedenham, 

 Norfolk. Mr. Woodward. At Lakenham, Norwich. Mr. Crowe. 



Perennial. July. 



Herb like the last, but the flowering part of the stem, or branches, 

 rises above the water, covered to the top with smaller, less 

 deeply cut, leaves, in the bosoms of which several whorls of 

 flowers are situated, the uppermost chiefly with stamens only ; 

 lowermost, less numerous, with pistils; intermediate ones often 

 with both. Pe/. small, white, deciduous. Siigmas thick, feathery. 

 The leaves are 5 in each whorl. 



439. SAGITTARIA. Arrow-head. 



Lin7i.Gen.470. Juss.46. Fl. Br. 1023. Lam. t. 776. Gartn.t.Si. 



Sagitta. Dill. Gen. 104.^.4. 



Nat. Ord. Tripetaloidece. Linn. 5. Juncii sect. 3. Juss. 13. 

 HydrocJiaridecc. Br. Pr. 344-. 



Barr.Jl. numerous. Cal. of 3 ovate, concave, permanent 

 leaves. Pet. 3, roundish, obtuse, with short claws, flat, 

 spreading, thrice the size of the calyx-leaves, and alter- 

 nate with them, deciduous. Filam. numerous, about 24, 

 awl-shaped, collected into a round head. Anth. vertical, 

 heart-shaped, much shorter than the petals. 



Fert.Jl. fewer, below the others. Cal. and Pet. as in them. 

 Germ, numerous, collected into a head, compressed, tu- 

 mid externally, tapering into very short styles, with sharp, 

 simple, permanent stigmas. Seeds numerous, obovate, 

 compressed, beaked, surrounded with a vertical, dilated, 

 compressed margin, broadest externally. '^'^ Embryo sim- 

 ple, undivided, folded." Gcertner. 



Aquatic herhs, rising above the surface. Stem none. Leaves 

 stalked, entire; arrow-shaped, or elliptical, i^/. large, 

 white and handsome, in several stalked ^whorls, on a tall 

 common stalk. 



1. S. sagittifolia. Common Arrow-head. 



Leaves arrow-shaped, acute. 



S. sagittifolia. Linn. Sp. P/. 1 4 1 0. fVilld. v. 4. 408. Fl. Br. 1 023 . 



Evgl. Bot. v.2.t. 84, Fl. Dan. t. 1 72. Dicks. H. Sice fuse. 1 5 . 



14. Ehrh.Hcrb. 140. 

 Sagitta. Rail Syn. 258. Bauh. Hist. v.3. p.2.779.f. Camer. 



Epit. 874./. 

 S.n. 1185. Hall. Hist.v. 2. 80. 



