KEY TO THE FAMILIES 



Veins usually anastomosing: scales usually 



clathrate 25. Polypodiaceae 



18b. Indusia usually present. 



Indusium inferior, globose with apical opening, 



or cleft into narrow segments 23. Woodsiaceae 



Indusium superior, orbicular or reniform, some- 

 times caducous or absent. 



Pinnae articulate to the rachis Nephrolepis 



Pinnae non-articulate to the rachis 24. Aspidiaceae 



II. SPERMATOPHYTA 



la. Ovules naked, not enclosed in an ovary; producing seeds on the 



face of a scale or bract : stigmas none A. GYMNOSPERMAE 



lb. Ovules borne in a closed ovary, which at maturity becomes the 



fruit: stigmas present B. ANGIOSPERMAE 



A. GYMNOSPERMAE 



la. Lvs. pinnately divided, evergreen: trunk short, usually unbranched: 



plants palm-like (Cycadales) 26. Cycadaceae 



lb. Lvs. simple: plants not palm-like. 

 2a. Seeds 1 (or rarely 2). drupe-like: embryo with 2 cotyledons. 

 3a. Lvs. fan-shaped, deciduous: tree with large trunk, deliquescent 



at maturity: seed drupe-like (Ginkgoales) 27. Ginkgoaceae 



3b. Lvs. scale-like, awl-shaped or needle-like, mostly evergreen: 

 excurrent trees or shrubs (Coniferae). 

 Anthers 2-celled: seeds solitary, axillary or terminal on lfy. 



shoots, surrounded by a fleshy aril: lvs. 3-10 cm. long. 29. Podocarpaceae 

 Anthers 3-8-celled: lvs. 2-8 cm. long. 

 Lvs. with 2 narrow stomatiferous bands beneath, 2-4 cm. 

 long: seed solitary, terminating a short shoot of the 

 infl., partly or wholly surrounded by a fleshy aril: 

 anthers 2-8-celled: brts. alternate or sub-opposite. .. 28. Taxaceae 

 Lvs. with 2 whitish stomatiferous bands beneath broader 

 than the 3 green lines, 2-8 cm. long: seeds 1 or 2; testa 

 with a fleshy outer layer and a thin woody inner layer: 



brts. opposite 30. Cepfialotaxaceae 



2b. Seeds 2-several, on the scales of a woody or berry-like cone 

 (ovulate strobilus): embryo with 2-15 cotyledons. 

 Cone scales imbricated, each subtended by a bract: seeds 2 to 

 each scale, winged: lvs. linear, needle-like, alternate or 



in fascicles 31 . Pinaceae 



Cone scales peltate or imperfectly imbricated, without bracts: 

 lvs. often acicular or scale-like. 

 Lvs. linear or subulate, spirally arranged or in opposite prs., 



often appearing in 2 ranks: seeds winged 32. 



Lvs. mostly small and scale-like, often decurrent: seeds 

 without wings 33. 



Taxodiaceae 

 Cupressaceae 



