KEY TO THE FAMILIES 



Srr.KiNGi.oM SPERM ATOPHYTA. 



Ovules and seeds borne on the face of a scale. Class 1. Gymnosper.m ak, 



Ovules and seeds contained in a closed cavity (ovary). 



Class 2. Angiospermae. 



Class I. GYMNOSPERMAE. 



Represented with us by 1 family. Pinaceae, 1. 



Class II. ANGIOSPERMAE. 



Cotyledons l; stem endogenous. Subclass 1. Monocotyledons. 



Cotyledons 2; stem exogenous. Subclass 2. Dicotyledons. 



Subclass I. MONOCOTYLEDONS. 



Leaves usually parallel-veined ; flowers mostly 3-merous or 

 6-merous. 



Perianth of minute scales or bristles, or wanting. 



Flowers aggregated on a spadix or scattered, the clusters surrounded at 

 base by a spathe, or foliaceous or membranaceous bract; periantb of 

 minute scales or bristles, or wanting. 

 Reed-like or flag-like marsh plants ; flowers unisexual. 



Typhaceae, 8. 

 Immersed aquatic plants. Naiadaceae, 9. 



Marsh or subaquatic plants; flowers perfect. Jdncaginaceae, 14. 



Minute floating plants. Lemnaceae, 77. 



Flowers in the axils of scales (glumes); perianth wanting. 



Glumes 2 to each flower. Gramineae, 18. 



Glumes 1 to each flower. Cyperaceae, 64. 



Perianth of 6 distinct chaff-like scales. Juncaceae, 79. 



Perianth petalold. 



Carpels distinct, numerous. Alismaceae, 16. 



Carpels united, usually 3, forming a 3-celled or 3-valved ovary. 



Ovary superior. Liliaceae, 82. 



Ovary inferior. 



Stamens 3; perianth regular. Iridaceae, 92. 



Stamens 1 or 2; perianth irregular. Orchidaceae, 93. 



