NORTH AMERICAN TREES 



CLASS GYMNOSPERM^ 



NAKED-SEEDED PLANTS 



EED-B EARING plants (Spermatophyta) form the division of the vege- 

 table world to which all trees except tree-ferns of tropical regions 

 belong. This subkingdom is composed of two classes: (i) Gymno- 

 spermse, or naked-seeded plants, and (2) Angiospermae, or covered- 

 seeded plants. 



The Gymnospermae have their ovules borne on the face of a scale, and not 

 enclosed in an ovary, and the ovules ripen into seeds which are not enclosed in a 

 pericarp but are usually contained in a cone of one kind or another, the cones of 

 pine-trees or fir-trees being familiar examples. All the Gymnospermae are woody 

 plants, most of them trees, a few shrubs. The order Finales, comprising the 

 Pine and the Yew families, is represented by many trees and shrubs of the north 

 temperate zone, most of them evergreens. 



Fruit a cone of many or few scales, beny-like in Juniperus. Pine Family. 



Fruit, in our genera, a fleshy disk partly surrounding the bony seed, or the seed naked. 



, Yew Family. 



