MONOECIA. POLYANDRIA. 211 



Order VII.— POLYANDRIA. 



748. CERATOPliYLT.,UM. X. (Horn wort.) 

 Masc. Calix many-parted. Corolla none. 

 Stauiina 16 to 20, very short. Jnthers tricuspid 

 date. Fem. Calix 6-Ieaved, imbricated. Co- 

 rolla none. Style 1, filiform. JWt 1- seeded. 



Aquatic plants with verticillated narrow leaves, dicho- 

 tomous uiid many-parted; flowers ariiUary, solitary; fruit 

 naked or spinose. 



Species. 1. C demersii7u. Fruit with 3 spines. 2. suli- 

 mersitm. Fruit spineless. — A genus of 2 species indige- 

 nous also to Europe. 



r49. MYRIOPHYLLUM. L. (Water Milfoil.) 

 Calix 4 -cleft. Petals 4, caducous. Stamina 

 4, 6, or 8. Germs 4, Styles none. Stigmas 

 pubescent. Seeds 4, coated. 



Aquatics with verticillated and pseudopinnate leaves; 

 flowers axillary, sessile and solitary; the upper verticills 

 masculine, the lower feminine. 



Species. 3. M. spicatnm: 2. rerticiUatuTni. Hab. From 

 Canada to Carolina, also in Lower Louisiana. 3. scabra- 

 turn. 4. heterophyllinn. 



*PTiLOPHYLLUM.t Flowcrs all hermaphrodite. 

 _ — C«/2\r 4-cIei"t. Petals none. Stamina. A^ very 

 short; anthers roundish. Styles xiont. Stigmas mi- 

 nute, pubescent, subcapitaie. Seeds 4y coated. 



Aquatic: leaves alternate, pseudopinnate, the upper- 

 most entire and serrate; flowers solitary, axillary, Librae- 

 teate at the base. Seed as in jlfynopk^lliwi, vvitli which 

 genus and Proserpinaca \ it appears intermediate. 



I*' Feather leaf," from ^r< Aew, a feather, and (pvXov^ a leaf. 

 This is the Piirshia of Mr. Rafinesque, but scarcely more than 

 a subg-enus. Onosmodium of Michaux is now called Purshia by- 

 professor Sprengel. 



tThe calix in this plant is frequently 4-cleft, and accompani- 

 ed by 4 stamens, styles and germs. 



