KEY TO THE ORDEKS. 



OTUles, and seeds, borne on the face of a bract or a scale : stigmas wanting. 



Class 1. GYMNOSPEHMAE. 

 Ovules, and seeds, in a closed cavity (ovary) : stigmas present. 



Class 2. ANGIOSPERMAB. 



1. Gymnospermae. 



Plants growing by a single terminal bud, with pinnate leaves circinate In verna- 

 tion : embryo prolonged into a spiral. Order CYCADALBS. 



Plants growing by lateral as well as by terminal buds, with scale-like, flat or needle- 

 like leaves not circinate : embryo not prolonged into a spiral. Order PINALES. 



2. Angiospermae. 



Cotyledon 1 : stem endogenous. Subclass 1. MONOCOTYLEDONS s. 



Cotyledons normally 2: stem exogenous (with rare exceptions). 



Subclass 2. DICOTYLEDONES. 



1. MONOCOTYLEDONES. 



Perianth rudimentary or wanting : flowers in the axils of dry or chaffy bracts (scales). 



Order POALES. 



Perianth of 2 distinct series : flowers not in the axils of dry or chaffy bracts. 

 Leaf-blades pinnately or palmately lobed, or compound : ovules solitary in each 

 carpel-cavity. Order ARECALES. 



Leaf-blades narrow, entire or essentially so, simple : ovules many in each carpel- 

 cavity. Order LILIALES. 



2. DICOTYLEDONES. 



Corolla wanting 



ting. 



Calyx wanting, at least in the staminate flowers. 

 Fruit 1-seeded : seeds without tufts of hairs. 



Gynoecium 1-carpellary : stigma 1 : ovule laterally attached and amphi- 

 tropous. Order LEITNERIALES. 



Gynoecium 2-carpellary : stigmas 2 : ovule erect and orthotropous or pen- 

 dulous and anatropous. 

 Pistillate flowers without a calyx : ovule erect and orthotropous. 



Order MYRICALES. 



Pistillate flowers with a calyx : ovule pendulous and anatropous. 

 Leaf-blades simple. 



Fruit a nut or an achene. Corylaceae in Order FAGALES. 



Fruit a drupe. Oleaceae in Order OLEALES. 



Leaf-blades compound : fruit a samara. Oleaceae In Order OLEALES. 

 Fruit many-seeded : seeds each with a tuft of hairs. Order SALICALES. 



Calyx present at least in the staminate or in the perfect flowers. 

 Flowers, at least the staminate, in aments, or ament-like spikes. 



Pistillate flowers separate at maturity : fruit a nut or an achene. 



Order FAGALES. 

 Pistillate flowers forming aggregate fruits : fruit drupe-like. 



Artocarpaceae In Order URTICALES. 

 Flowers, at least the staminate, not in aments. 

 Ovary superior. 



Gynoecium of 1 or several and distinct carpels : stigma and style 



solitary. 

 Carpel solitary. 



Style lateral and oblique. Petiverlaceae In Order CHEXOPODIALES. 

 Style axile, erect. 



Ovary neither enclosed nor seated in a hypanthium or a 



calyx-tube. 



Ovary enclosed in or seated in a hypanthium or a calyx- 

 tube. 

 Stamens borne under the gynoeclum. 



Pisoniaceae in Order CHENOPODIALES. 

 Stamens borne on the hypanthium or adnate to the 

 calyx-tube. Order THYMELEALES. 



Carpels several. 



Stamens inserted below the ovary. Families in Order RAXALES. 

 Stamens inserted on the edge of a cup-shaped hypanthium. 



Rosaceae In Order ROSALES. 

 vii 



