22 Key to the Si/stem of 



7 */ / 



98. Petals absent 99 



Petals usually developed, sepalaceous ... ... ... 100 



99. Leaves much elongated. 



Swamp-plants ; staminate and pistillate flowers always 

 distinct, crowded into cylindric spikes or into headlets ; 

 sepals and petals scale-like or capillary ; stamens few or 

 many ; stigmas one or two ; fruit one- or two-celled ; 

 seeds solitary ; embryo within the albument. 



Typhaceae. 483 



Minute frond-like organs instead of leaves. 



Floating plants ; sepals and petals nonet; stamens one or 

 two ; fruit one-celled ; albument enclosing the embryo 

 or absent. Lemnaceae. 484 



100. Seeds without any albument, embryo comparatively 



large. 



Aquatic, rarely terrestrial plants, often floating ; sepals 

 three or less or absent ; petals three or less, often sepal- 

 like, never bright- colored, often succulent, minute or 

 absent ; fruit consisting of distinct or coherent fruitlets. 

 Figure 120. Pluviales. 485 



Seeds with albument, embryo comparatively minute 101 



101. Embryo placed within the albument or contained in 



an opening near the surface of the albument ... 102 



Embryo placed outside the albument... ... ... 103 



102. Stamens and pistils never in the same flowers. 



Palms, mostly superb plants, often tall, sometimes climbing ; 

 flowers seldom showy ; sepals three, equal, and petals 

 three, equal, all frequently glumaceous ; stamens often 

 six ; stigmas three ; fruit seldom very small, usually one- 

 celled and one-seeded, or rarely consisting of three dis- 

 tinct fruitlets, always indehiscent ; embryo comparatively 

 minute, placed in an opening near the surface of the 

 albument. Falmae. 492 



Stamens and pistils usually in the same flowers. 



Rushes ; flowers very small ; sepals three and petals three, 

 similar to each other and glumaceous ; stamens three or 

 six ; stigmas three ; fruit always very small, longitxidinally 

 dehiscent, one- or three- celled ; seeds erect ; embryo 

 minute, placed within the albument. Figure 1 23. 



Jimceae. 493 



