SYNOPSIS OF THE FAMILIES 19 



surrounded by a fleshy cup or aril (Taxus). Albumen fleshy; embryo straight. 

 Trees or shrubs with numerous small alternate, opposite or fascicled leaves and 

 very inconspicuous flowers. 



Sub- Kingdom II. Cryptogamic or Flowerless Plants. Plants not provided 

 with stamens and ovules as in Phanerogams. Reproductive organs are minute 

 spores contained in sporangia ; no seeds formed. 



Phylum III. Pteridophyta (Fern-like plants). Plants with true leaves, roots, 

 and vascular tissue as in Flowering Plants. 



Filices. Ferns. Plants usually with underground stems (creeping or short 

 ck root-stocks). Leai 

 angia on the under side. 



thick root-stocks). Leaves (fronds) large, usually compound, bearing the spor- 



undei 



Equisetaceae. Horse-tails. Main stems deep underground, sending up 

 aerial shoots either bearing whorls of green branches with minute scale-like 

 whorled leaves, or simple, colourless and terminated by a cone of whorled scales 

 bearing several sporangia on their lower surfaces. 



Lycopodiaceas. Clubmosses. Leaves small, but larger than in horse-tails, 

 spirally arranged or scattered, not whorled. Sporangia singly on the upper 

 sides of the cone scales. 



Selaginellaceae. Shoots flat ; leaves generally in two sets, dorsal, small, 

 adpressed to stem, ventral outstanding. Cones like those of Lycopodiaceae. 

 Spores of 2 kinds, megaspores and microspores, in separate sporangia. 



NOTE. 



It should be borne in mind by students that many plants are very variable, 

 and that sometimes the commonest form in Britain is not typical of the plant as 

 known on the Continent ; and especially is this the case in the Mediterranean 

 region, where physical conditions are so different. Moreover, it is well known 

 that the habitats of certain species are by no means the same in every country 

 where they grow, though in most cases there is a general similarity. Many of 

 the British plants mentioned in this book are described from French specimens. 

 We may, however, find that several plants known by the same name in England 

 and on the Continent of Europe are in reality different species. 



