GENERAL KEY. 



SUBKINGDOM PTERIDOPHYTA. 



Plants producing no flowers and seeds but spores which de- 

 velop into flat or irregular prothallia bearing the reproduc- 

 tive organs. 



Spores of one kind only. page 



Sporanges borne on back or margin of fronds, or in special spikes 



or panicles FILICALES 7 



Sporanges borne beneath shield-shaped scales in a terminal spike; 



stems jointed, sheathed at nodes EQTJISETALES 14 



Sporanges solitary in the axils of the leaves. 



Lycopodiacbae in LYCOPODIALES 15 



Spores of two kinds, large and small. 



Sporanges enclosed in sporocarps SALVTNIALES 14 



Sporanges in the axils of the leaves. 



Selaginellaceae and Isoetaoeae in LYCOPODIALES 17 



SUBKINGDOM SPERMAPHYTA. 



Plants producing flowers, whose essential organs are stamens 

 and pistils, the latter producing true seeds. 



1. Ovules not enclosed in an ovary. Class I. GYMNOSPERMAE 18 



2. Ovules enclosed in an ovary. Class 2. ANGIOSPERMAE 20 



Embryo with 1 Cotyledon; fibro-vascular bundles scattered through 

 pith; leaves mostly parallel-veined, flower parts usually in threes. 



Subclass I. MONOCOTYLEDONES 20 



A. Flowers aggregated on a spadix; or plants minute, floating free, 



the flowers few or solitary on the margin or back of thallus. 



AEALES 88 



B. Flowers not collected on a spadix. 



Flowers destitute of corolla-like peiianth. 



Flowers in the axils of dry, chaffy scales; arranged in spikes 



or spikelets GRAMINALES 26 



Flowers not in the axils of dry, chaffy scales; aquatic or marsh 

 plants. 

 Perianth represented by bristles or chaff -like scales; flow- 

 ers monoecious, spicate or capitate; endosperm mealy or 



fleshy PANDANALES 20 



Perianth none; endosperm none or very little. 



NAIADALES 21 

 Flowers with corolla-like perianth. 



Flowers regular (except Commelina) ; the parts of the usually 

 complete flowers mostly in 3's or 6's (except most 

 Naiadales). 



Note.— Page refers to orders, except when in italics, leading then to genus. 



'After name of order indicates that this order properly belongs to the other series, e. g., 

 Frimulales are Gamopetalae but Qlaux is an exception. 



