xxxvi 



INTRODUCTION. 



Ovule and seed solitary. Leaves stipulate. 

 Stipules sheathing. Leaves alternate. 

 Stipules scarious. Leaves opposite. 

 Stipules not sheathing- nor scarious. 

 Flowers perfect Achenium 2-lobed, spiny. 

 Flowers imperfect. 

 Herbs. Stems twining. Leaves 3 - 5-lobed. 



Stems not twining. Leaves serrate or entire. 

 Trees or shrubs. 



Juice watery. Flowers single or clustered. 

 Juice milky. Flowers included in a fleshy receptacle. 

 Ovule and seed solitary. Leaves without stipules. 

 Stamens more numerous than the calyx-lobes. 

 Anthers opening by valves. 

 Anthers opening lengthwise. 

 Calyx 6 - 6-parted. 

 Calyx entire. Berry oval. 



Stamens equalling in number or fewer than the calyx-lobes. 

 Flowers with scarious bracts. 

 Flowers without scarious bracts. 

 Calyx corolla-like, plaited. 

 Calyx herbaceous. Styles 2. 

 Ovary2-12-celled. 

 Leaves whorled. 



A heath-like shrub. Calyx of imbricated scales. 

 A prostrate annual. Calyx corolla-like. 

 Leaves opposite. 



Fruit a single samara. Calyx minute, persistent. 

 Fruit a double samara Calyx deciduous. 

 Fruit a drupe. 



Flowers perfect. Stamens on the calyx. 

 Flowers dioecious. Stamens hypogynous. 

 Fruit a many-seeded capsule. Herbs. 

 Leaves alternate. 



Ovules and seeds 1 - 2 in each cell. 

 Flowers mono-dioecious. Fruit a drupe or capsule. 

 Flowers polygamous. Capsule 3 - 4-winged. 

 Flowers perfect or polygamous. 

 Fruit a berry. Calyx colored. 

 Fruit a samara. Leaves stipulate. 



POLYGONACE^, 384 

 ILLECEBRE.E, 45 



PETIVERIE^, 374 



CANNABINACE^. 414 

 URTICACEJE, 411 



ULMACE^E, 416 

 MORACE^I, 414 



LAURACE.E, 393 



POLYGONACE^, 384 

 THYMELEACE.E, 395 



AMARANTACE^E, 378 



NYCTAGINACE.E 372 

 CHENOPODIACE^, 375 



EMPETRACE^E, 410 

 MOLLUGINEJE, 45 



FRAXINEJE, 369 

 ACERACE^S, 80 



RHAMNACE^;, 72 

 ORESTIEREJE, 36& 

 LYTHRACE^I, 133 



EUPHORBIACEJE, 399 

 SAPINDACE^E, 78 



PHYTOLACCACE^:, 374 

 ULMACEjE, 416 



Ovules and seeds numerous in the cells. Capsule circumscissile. 

 Capsule 3-celled Flowers solitary. PORTULACACE.3S, 43 



Capsule 5-celled Flowers cymose. CRASSULACEJE, 149 



SUBCLASS II. GYMNOSPERMOUS EXOGENOUS PLANTS. 



Ovules naked (not contained in an ovary), supported by an open scale 

 or leaf, or else terminating a branch, and fertilized by the direct applica- 

 tion of the pollen. 



Stem branching. Leaves simple. 



Stem simple, palm-like. Leaves pinnate. 



CONIFERS. 431 

 CYCADACKE, 437 



