ANALYTICAL KEY. lix 



IV.— ANALYTICAL KEY 



To the Natural Orders and Anomalous Genera of the 'British Flora. 



The heads of division adopted in the following Key are necessarily artificial, 

 being solely intended to assist the beginner in finding out the name of his plant, 

 and its place in the system, like the letters of the alphabet in an index. They 

 are not classes or groups of Orders, for the same Order will be found re- 

 peated under different heads. At the same time, it has been the endeavour so 

 to frame them as to call the student's attention to some of the most prominent 

 characters of the great natural divisions. 



I. FLOWEK1NG PLANTS. 



(Flowers compound, consisting of several florets in a common invo- 

 lucre, without separate calyces. Anthers united in a cylinder round 

 the style 2 

 Flowers distinct, or if in a head, having the anthers free .... 3 

 |" Ovary and fruit containing a single seed, and appearing like a seed 



2 < under the floret Composite Fam. (p. 407.) 



[ Ovary and fruit two-celled, with several seeds . Jasione Gen. (p. 507.) 

 f Perianth double, consisting of a calyx (sometimes reduced to a scarcely 



3 < prominent ring) and a corolla 4 



[ Perianth single (its segments all calyx-like or all petal-like) or none 85 



. J Corolla consisting of several distinct petals 5 



\ Corolla of one piece, the petals united, at least at the base .... 8 



- f Ovary free, within or above the petals ........... 6 



\ Ovary inferior, adherent to the base of the calyx, and below the petals 46 



fi f Ovaries several in the same flower, the carpels distinct or deeply divided 9 



\ Ovary solitary (simple or compound) entire or slightly divided ... 7 



,_ J Corolla regular, the petals equal and similar to each other . . . . 15 



\ Corolla irregular 41 



s f Ovary inferior or adherent, below the insertion of the corolla ... 51 



X Ovary superior or free, within the tube or base of the corolla ... 57 



Polypetals with several free, distinct ovaries or carpels. 



C Stamens united in a ring or column enclosing the style. Ovaries in a 

 qj ring round the axis 10 



] Stamens free. Ovaries quite free, each with a distinct style or stigma, 



L without a central axis 11 



1n J Stamens 5 or 10, shortly united at the base. Geranium Fam. (p. 158.) 



\ Stamens indefinite, united in a column . . . Mallow Fam. (p. 151.) 



f Stamens definite in number (as many, twice, or thrice as many as the 

 11 ^ petals) . 12 



(_ Stamens indefinite 13 



19 f Leaves fleshy. Sepals and petals 4 or more . Crassula Fam. (p. 291.) 



\ Aquatic plants not fleshy. Sepals and petals 3. Alisma Fam. (p. 793.) 

 ,„ J Leaves without stipules. Stamens inserted on the receptacle ... 14 



\ Leaves with stipules. Stamens on the calyx . • . Rose Fam. (p. 234.) 

 ..^ J Sepals or petals, or both, 4 or more . . . Ranunculus Fam. (p. 1.) 



\ Sepals and petals, 3 each Alisma Fam. (p. 793). 



