KEY TO THE ORDERS. 



SUBKINGDOM SPERMATOPHYTA. 



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



Class 1. GYMNOSPERMAE. 

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



Class 2. ANGIOSPERMAE. 



CLASS 1. Gymnospermae. 



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

 leaves : embryo with 2-several cotyledons. Order FINALES. 



CLASS 2. Angiospermae. 



Cotyledon 1 : stem endogenous. Subclass 1. MONOCOTYLEDONES. 



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



Subclass 2. DICOTYLEDONES. 



SUBCLASS 1. MONOCOTYLEDONES. 



Perianth rudimentary or degenerate, the members often bristles or mere scales, not 



corolla-like, or wanting. 

 Flowers not in the axils of dry or chaffy bracts (scales or glumes). 



Perianth of bristles or chaffy scales. Order PANDANALES. 



Perianth fleshy or herbaceous, or wanting. 



Fruit baccate : endosperm present. Order ARALES. 



Fruit drupaceous : endosperm wanting. Order NAIADALES. 



Flowers in the axils of dry or chaffy, usually imbricated, bracts (scales or 



glumes). Order POALES. 



Perianth of 2 distinct series, the inner series usually corolloid. 



Gynoecium of distinct carpels. Order ALISMALES. 



Gynoecium of united carpels. 



Endosperm mealy. Order XYRIDALES. 



Endosperm fleshy, horny or cartilaginous. 



A. Ovary, and fruit, superior. 



Inflorescence not a fleshy spadix. Order LILIALES. 



Inflorescence a fleshy spadix subtended by a spathe. Order ARALES. 



B. Ovary, and fruit, wholly inferior or half-inferior. 



Endosperm present and usually copious. Order AMARYLLIDALES. 



Endosperm wanting. 



Flowers regular, monoecious or dioecious : aquatic plants. 



Order HYDROCHARITALES. 

 Flowers irregular, perfect : terrestrial or epiphytic plants. 



Order ORCHIDALES. 



SUBCLASS 2. DICOTYLEDONES. 



A. Corolla wanting, except in the pistillate flowers of Juglans (Juglandaceae). 

 Calyx wanting, at least in the staminate flowers. 

 Herbs. 



Flowers mainly perfect. 



Seeds solitary in each carpel or in each cavity of the ovary : endo- 

 sperm present. 

 Flowers spicate : styles wanting : stigmas sessile. 



Order PIPERALES. 

 Flowers axillary : styles present. 



Callithichaceae in Order EUPHORBIALES. 

 Seeds numerous in each cavity of the ovary : endosperm wanting. 



Podostemaceae in Order ROSALES. 



Flowers monoecious or dioecious. Order EUPHORBIALES. 



Trees or shrubs : flowers monoecious or dioecious, or polygamous. 

 Fruit 1-seeded : seeds without tufts of hairs. 



Ovules 1 or 2 in each cavity of the ovary : flowers not in heads. 

 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. 



