154 REPORT OF NEW JERSEY STATE MUSEUM. 



aa. Flowers not inclosed, in husk-like glumes. 



b. Aquatic plants, entirely submerged or with some of the leaves float- 

 ing on the surface. 



c. Plant a minute floating disc with several roots below or a 

 minute floating globule. Lemnacece, p. 318 



cc. Stems branched and leafy, leaves long and grass-like or ovate. 

 d. Flowers inconspicuous, axillary or in short spikes. 



Najadacea, p. l6tt 

 id. Flowers star-like, yellow, raised above the surface on 

 slender pedicels. Heteranthera dubia, p. 327 



ccc. Stems mostly simple, leaves short, linear, whorled. 



Philotria, p. 173 

 cccc. All leaves from the root, long and ribbon-like, flowers on sepa- 

 rate thread-like scapes. Vallisneria, p. 173 

 ccccc. Leaves basal in an erect tuft, lanceolate, flat or awl-shaped, 

 flowers projecting above the surface. 

 d. Flowers showy, white, in a spike remotely whorled. 



Sagittaria, p. 169 

 dd. Flowers minute, forming a compact button-like head. 



Briocaulon, p. 323 

 bb. Erect plants, growing in water, swamps or dry ground. 

 c. Flowers regular. 



d. Leaves whorled or palmately divided. 



e. Leaves in one whorl of three, flowers solitary. 



Trillium, p. 350 



ee. Leaves in two whorls of more than three, flowers 



several. Medeola, p. 350 



eee: Leaves in many whorls, flowers large, red or orange. 



Lilium, p. 345 

 eeee. Leaves one or two, palmately divided. 



Ariscema, p. 314 

 dd. Leaves not whorled or palmately divided. * 



e. Leaves all radical. 



/. Leaves sagittate. 



g. Flowers white, in a remotely whorled 

 spike. Sagittaria, p. 169 



gg. Flowers blue, in a compact spike. 



Pontederia, p. 327 

 ggg. Flowers minute, on a fleshy spadix, in- 

 cased in a convolute spathe. 



Peltandra, p. 315 

 ff. Leaves oval, ovate, etc. (at least 25 mm. wide). 

 g. Leaves numerous. 



h. Flowers minute, on a fleshy spadix,. 

 no parianth. 



i. Spadix covered by a hood-like 

 spathe, appearing before the 

 large cabbage-like leaves. 



Spathyema, p. 316 



