8 ANALYTICAL KEY 



SUBDIVISION II. ANGIOSPERMS 

 < >\ ules borne in a closed ovary, which at maturity becomes the fruit. 



CLASS 1. MONOCOTYLEDONS 



MS mostly without central pith or annular layers, but having the woody 

 fibers in small separate bundles which appear, in cross section, irregularly 

 dispersed throughout the cellular tissue. Leaves mostly parallel- veined. 

 Kmbryo with a single cotyledon and the first leaves in germination alternate. 



of the flower usually in threes or sixes, never in fives. Our species 

 herbaceous. 



THALLOID AQUATICS WITHOUT TRUE STEMS OR LEAVES 



The plant body lens-shaped, ellipsoidal, or flask-shaped, floating 



18. LEMNACEAE, 105 



PLANTS WITH STEMS AND LEAVES 



PERIANTH FREE FROM THE OVARY OR WANTING 



Perianth wanting, or of scale-like or bristle-form divisions. 



Flowers inclosed or subtended by imbricated chaff-like scales 

 (glumes) ; grass-like plants with jointed stems, sheathing and 

 mostly narrow leaves, and one-seeded fruit. 



Stems hollow, round, or flattened; leaf-sheaths split; anthers at- 

 tached by the middle 16. GRAMINEAE, 38 

 Stems solid, usually more or less triangular; leaf-sheaths not split; 



anthers attached at the base 17. CYPERACEAE, 84 



Flowers not inclosed in chaff-like scales (though sometimes in in- 



volucrate heads). 

 Immersed aquatics, branching and leafy, the upper leaves often 



floating 12. NAIADACEAE, 33 



Terrestrial or marsh plants. 



Flowers monoecious or dioecious. 



Flowers in cylindrical spikes 10. TYPHACEAE, 31 



Flowers in lateral heads 11. SPARGANIACEAE, 32 



Mowers perfect. 



Ovaries 3-6, separating at least when ripe 13. JUNCAGINACEAE, 36 



Ovary single, of 3 carpels 21 JUNCACEAE, 108 



I'< ri<inth always present, herbaceous or colored, never scale-like nor bristle- 



j <>r in. 



numerous, in a head or ring 14. ALISMACEAE, 37 



I , cells or placentae mostly 3. 

 mani all alike ami fertile. 



.ry of nearlv separate carpels 13. JuNCAGTNACEAE, 36 



: v often angled or lobed but not deeply cleft. 



i feet ; plants not climbing. 

 1 )i visions of t he perianth alike or nearly so. 



Plant nixh-like; perianth small, greenish or purplish- 



l-iown 21. JUNCACEAE, 108 



I'lant not rush-like. 



