188 



DE CANDOLLES SYSTEM. 



181. Pistiacea. Floating plants, with very cellular, lenti- 

 cular, or lobed stems and leaves. Flowers from the margin 

 of the stems, inconspicuous, naked. Stamens definite. Ovary 

 superior, 1 -celled, with erect ovules. Fruit membranous or 

 capsular, 1- or more seeded. Embryo either in the axis of 

 fleshy albumen, and having a lateral cleft, or at the apex of 

 the nucleus. 



USES. Acrid plants of no importance. 



TYPICAL GENERA. Lemna, Pistia. 



SUBCLASS III. GLUMACE.E. 



182. Cyperacete. Leaves with their sheaths entire. Stem 

 solid. Flowers consisting of imbricated solitary bracts. Pe- 

 rianth none. Stamens definite, 1,2, 3, 4, 5, 6, 7, 10, 12 ; 

 anthers fixed by their base. Ovary often surrounded by 

 bristles ; ovule erect ; style single, trifid or bifid. Nut crus- 

 taceous or bony. Embryo lenticular, within the base of the 

 albumen. 



hyp08yi """ bris ""- 2 ' A 



