502 NATURAL HISTORY OF PLANTS. 



Sepals (?) 2, 3, dentiform, unequal or equal, sometimes scarcely 

 perceptible. Petals (?) 2, lateral, longer membranous, concave or 

 cucullate (sometimes 0). Stamens 2, opposite to petals (or more 

 rarely 1, 3) ; filaments erect short, sometimes strong ; anthers basi- 

 fixed oblong; cells 2, laterally riniose. Germen inferior, 1-locular ; 

 styles 2, subulate or capitate, richly papillose. Ovule 1, laterally 

 inserted under apex of cell, descending, anatropous or (?) peritropous. 

 Fruit drupaceous or coriaceous ; subglobose or 3-gonal ; putamen 

 crustaceous. Seed descending ; testa thin ; albumen copious farina- 

 ceous ; embryo minute subapical. — Perennial herbs, scapiferous, 

 glabrous or hispid or scabrous ; rhizome often thick creeping ; leaves 

 alternate, all radical, appendiculate stipuliform sometimes intermixed; 

 petiole often thick ; limb ovate, suborbicular or corda to-rotimdate, 

 sometimes subflabelliform, simple or lobed, often coriaceous fleshy 

 rugose ; nerves strong ; flowers (very small) either spicate, or densely 

 crowded on the twigs of a thick compound branch, 2-bracteolate ; 

 inflorescence 1- or oftener 2-sexual; male flowers above. (South, 

 and east. Africa, Java, Oceania, Juan Fernandez, Andean South 

 America.) — See p. 482. 



VII. HIPPUEIDE^. 



23. Hippuris L. — Flowers hermaphrodite or more rarely poly- 

 gamous ; receptacle concave ovoid or subglobose, mouth entire 

 or unequally crenulate. Perianth 0. Stamen 1 (very rarely 2), 

 epigynous, anteriorly inserted at top of receptacle ; filament erect 

 subulate ; anther ovate basifixed, introrsely 2-rimose. Germen 

 inferior, adnate to receptacle within, 1-locular; style subulate, 

 entirely stigmatose. Ovule 1, inserted under apex of cell, descend - 

 ing ; micropyle introrsely superior. Fruit ovoid drupaceous, slightly 

 fleshy ; putamen hard. Seed 1, descending, embryo slightly fleshy 

 fatty ; radicle of straight axile terete embryo superior. — Glabrous 

 aquatic perennial herbs ; rhizome turfy creeping ; branches erect 

 thick simple; leaves verticillate (4-12-nate) narrow linear entire; 

 flowers (very small) axillary solitary sessile. (Europe, temp, and 

 north. Asia, north, and antarctic America.) — See p. 484. 



