2 Equisetaceae, Lycopodiaceae 



inner surface of the lamina of the sporangiophore. 

 Homosporous or (in some extinct forms) heterosporous. 



Order Ec[uisetales (including all living forms). 

 Homosporous. 



Family Equisetaceae. Rhizomes subterranean 

 often bearing distinct sterile and fertile shoots. Bases 

 of leaf-whorls united into sheaths enclosing the base of 

 the internode above. Branching axillary. Epispore 

 splitting into two spirally wound threads ielatei's). Pro- 

 thal/i hrsinch.Qd, often functionally dioecious, AntJieridia 

 and archegonia sunken. Speiinatozoids multiciliate. 



Only genus : Equisetum. 



Class 2. LYCOPODIARIAE. Leaves usually 

 small in relation to stem. Stem with one or more 

 haplosteles•^. Sporangia single in axils, or on adaxial 

 faces of fertile leav^es. Homosporous or heterosporous. 

 Spermatozoids biciliate. 



Order i. Lycopodiales. Small leaved herbs of 

 erect or creeping habit. Sporophylls mostly aggregated 

 in cones. 



Suborder i. Eligulatae. Homosporous forms 

 without ligule. 



Family LYCOPODIACEAE. Erect or suberect herbs 

 with modified haplostele. ProtJialli generally subter- 

 ranean, saprophytic, with symbiotic fungus. Embryo 

 often living a subterranean life for some years. 



Only British genus : Lycopodium. 



t Haplostele. The cauline vascular cylinder in its simpler 

 form, in which the centre is occupied by xylem, and this is typically 

 surrounded by phloem, pericycle and endodermis (Brebner, Ann. 

 Bot. 1902, p. 523 and Tansley, Evolution of Filicinean Vascutar 

 System.^ 1908). 



