KEY TO THE FAMILIES OF CLASS I. 



11] 



POKEWEED F. 191 



Pistil only one, either simple or formed of two or more with their ovaries united. 

 Styles 10. Fruit a 10-seeded berry, 

 Styles or stigmas 2 or 3. 



Herbs with sheaths for stipules, and entire leaves. 



Herbs with separate stipules, and compound or cleft leaves. 



Herbs without stipules, and 



Without scaly bracts. Flowers small and greenish. 

 With scaly bracts around and among the flowers. 

 Shrubs or trees, with opposite leaves. Fruit a pair of keys. 

 Shrubs or trees, with alternate leaves and deciduous stipules. 

 Stamens on the throat of the calyx, alternate with its lobes. 

 Stamens on the bottom of the calyx. 

 Style one: stigma 2-lobed. Fruit a key. Leaves pinnate, 

 Style or sessile stigma one and simple. 



Calyx tubular or cup-shaped, colored like a corolla. 

 Stamens 8, on the tube. Shrubs: leaves simple, 

 Stamens 4, on the throat. Herbs : leaves compound. 

 Stamens 5 or less on the receptacle. Calyx imitating a monopetalous 

 funnel-shaped corolla: a cup outside imitating a calyx. 

 Herbs with opposite leaves, Mirabilis 



Calyx of 6 petal-like sepals colored like petals : stamens 9 or 12 : anthers opening 



by uplifted valves. Aromatic trees and shrubs. Laurel 



Calyx in the sterile flowers of 3 to 5 greenish sepals: stamens the same number. 



Flowers moncecious or dioecious. Nettle 



Buckwheat 

 Hemp 



goosefoot 



Amaraxtit 



t Maple 



Buckthorn 



Elm 



Ash in IOlive 



Mezebeum 

 Burnet in fEosE 



F. 192 

 F. 196 



F. 191 

 F. 192 

 F. 140 



F. 138 

 F. 196 

 F. 189 



F. 195 

 F. 146 



F. 191 

 F. 194 

 F. 195 



B. Flowers one or both sorts in catkins or catkin-like heads. 



Twining herbs, dioecious : fertile flowers only in a short catkin. Hop in the Hemp F. 196 



Trees or shrubs. 



Sterile flowei's only in catkins. Flowers monoecious. 



Leaves pinnate. Ovary and fruit (a kind of stone-fruit, without an involucre). Walnut F. 197 

 Leaves simple. Nuts one or more in a cup or involucre, Oak F. 197 



Both kinds of flowers in catkins or close heads. 

 Leaves palmately veined or lobed. 



Calyx 4-cIeft, in the fertile flowers becoming berry-like. Mulberry, &c. in Nettle F. 195 



Plane-tree F. 196 



Calyx none : flowers in round heads, 

 Leaves pinnately veined. 



Flowers dioecious, one to each scale. Pod many-seeded, 

 Flowers monoecious, the fertile ones 2 or more under each scale. 

 Flowers only one under each fertile scale. Fruit one-seeded, 



Willow F. 199 



Birch F. 199 



Sweet-Gale F. 198 



Subclass II. — GYMNOSPEEMS. 

 Proper pistil none ; the ovules and seeds naked, on the bottom or inner face of an 



open scale, as in Pines, or without any scale at all, as in Yew, 



Pine Famiiy, 20] 



