KEY TO THE FAMILIES 



SUBKINGDOM SPERMATOPHYTA. 



Ovules and seeds borne on the face of a scale. Class 1. GYMNOSPERMAE. 

 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 1 ; 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; perianth 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. 



