GENERAL KEY TO THE FAMILIES 



I. Ovules not enclosed in any ovary but borne naked on 



the face of a scale. 

 Fruit a cone, of many or few scales, berry -like in Juniperus 

 Fruit, in our genera, a fleshy disk partly surrounding a 

 bony seed, or the seed naked. 



II. Ovules enclosed in an ovary. 



A. Embryo with one cotyledon; stem not differentiated 



into bark, wood and pith; Jeaves mostly parallel- 

 veined. 

 Leaves pinnately or palmately compound; ovule i in 



each cavity of the ovary. 

 Leaves simple, elongated; ovules many in each cavity 

 of the ovary. 



B. Embryo normally with two cotyledons; stem differ- 



entiated into bark, wood, and with pith, at least 

 when young; leaves mostly net-veined. 

 1. Petals normally separate to the base, or wanting. 

 I. Leaves reduced to appressed scales; branches 

 loosely jointed; tropical tree, introduced in 

 Florida. 

 2 Leaves not reduced to appressed scales, though 

 sometimes small or caducous; branches not 

 loosely jointed. 

 a. Petals none, except in the pistillate flowers 

 of the Walnuts (Juglans), and in the 

 Olax Family. 

 * Caljrx none, except in the Walnut Family; 

 flowers, at least the staminate ones, in 

 catkins. 

 Leaves simple. 

 Fruit many-seeded; seeds with a tuft of hairs 



at one end. 

 Fruit only oiie-seeded. 

 Stigmas 2. 



Style stigmatic above. 

 Leaves odd-pinnate; fruit a nut enclosed in a 

 husk. 

 ** Calyx present. 

 Leaves odd-pinnate; staminate flowers in catkins. 

 Leaves simple. 

 Flowers, at least the staminate ones, in catkins. 

 Both staminate and pistillate flowers in cat- 

 kins. 



PAGE 



Class Gynmospennse. i 



Pine Family. 3 



Yew Family. 122 



Class Angiospennse. 129 



Subclass MONOCOTYLE- 



DONES. 130 



Beefwood Family. 



162 



Birch Family. 



240 



