60 HENRY S. CONARD 



Division 1. THALLOPHYTA. Reproduction by spores of various kinds, or by 

 gametes, or both. No protected embryo. Plant body with little or no 

 differentiation of vegetative organs, unicellular or multicellular. — A mis- 

 cellaneous group of algae, fungi and lichens. 



Division 2. EMBRYOPHYTA (Archegoniatae). Oogamic by eggs in arche- 

 gonia or embryo sacs. Fertilized egg becoming a multicellular embryo, 

 contained at first within the tissues of the parent. Alternation of genera- 

 tions. Plant body showing leaf and stem, and ultimately root and flower. 

 Subdivision 1. Atracheata (Bryophyta). — Thalloid or phylloid plants of 

 small size, without roots or tracheary tissues. Gametophyte alone lives 

 independently, the sporophyte being parasitic upon it. 

 Subdivision 2. Tracheata (Vasculares). — Plants with root, stem and leaf 

 containing tracheary tissues. Sporophyte lives independently of game- 

 tophyte, the latter becoming successively reduced almost to obliteration. 

 Series 1. lycopsida. — Palingenetically microphyllous. Tracheary tissue of 

 stem protostelic, or siphonostelic and cladosiphonic. Sporangia few, 

 adaxial. Leaves narrow, whorled or crowded. 



Order 1. Lycopodiales 



Suborder 1. Isosporineae (Isosporeae; Eligulatae) 

 Family 1. Lycopodiaceae 



2. Psilotaceae 



Suborder 2. Heterosporineae (Heterosporae; Ligulatae) 



Family 3. Lepidodendraceae 



4. Isoetaceae 



5. Selaginellaceae 



Order 2. Equisetales 



Family 6. Sphenophyllaceae 



7. Calamitaceae 



8. Equisetaceae 



Series 2. pteropsida. — Palingenetically megaphyllous. Tracheary tissue of 

 stem protostelic, or siphomostelic and primarily phyllosiphonic. Spor- 

 angia numerous or few, primarily abaxial. 

 Class 1. Aspermae. — Fern plants, wholly lacking seed-like structures 

 (Filicales of Gray's Manual and Jeffrey) 



Subclass 1. Eusporangiatae 

 Order 1. Ophioglossales 



Family 1. Ophioglossaceae 

 Order 2. Marattiales 



Family 2. Asterothecaceae 



3. Marattiaceae 



Subclass 2. Leptosporangiatae 

 Order 3. Osmundales 



Family 4. Osmundaceae 

 Order 4. Filicales 

 Suborder 1. Isosporineae 



