106 PLANTS OF MASSACHUSETTS. 



and the fruit has 3 spines upon it. Stem long and slender, float- 

 ing, with whorled leaves in eights ; flowers axillary, solitary, very 

 minute ; found in ditches in Europe, and in similar places in 

 Nantucket ; July. 



2. Monopetalous Plants. 



We come now to a subdivision of the plants of this class, which 

 is artificial, and yet very important in ascertaining the plants, and 

 easily distinguishing them. The corolla is monopetalous, or the 

 supposed divisions of the petals cohere into a tube. Only a few 

 of the polypetalous corollas cohere at the base so as to be mono- 

 petalous, and form exceptions to this arrangement. 



ORDER 173. PYROLACEiE. The Winter-Green 



Tribe. 



Calyx 5-leafed, inferior, and persistent, with an hypogynous 

 corolla of one petal, regular, 4 or 5-toothed ; stamens hypogy- 

 nous, double the number of the divisions of the corolla ; ovary 

 superior, 4 or 5-celled, many-seeded ; style one, often declined 

 towards one side ; stems round, scaly ; flowers in terminal ra- 

 cemes, seldom solitary. 



The plants love the woods, and abound in the northern tem- 

 perate zone. 



The species of this order seem to have no very distinguishing 

 properties. 



Pyrola. L. 10. 1. Winter Green. 



A name considered as a diminutive of Pyrus, and the common 

 name, from many of the species being evergreen. Astringent and 

 tonic. The plants, though not very handsome, are singular and 

 interesting ; 7 species are found in the State, and about 12 in 

 North America. Calyx minute, 5-cleft, or 5-parted ; capsule 

 5-celled, and stigma 5-lobed. 



P. rotundifolia. L. Shin Leaf. A native of open woods 

 in a light soil, bearing 2 or 3 roundish leaves at the base, and the 



