NATURAL ORDERS. lxix 



.. n i J Three short styles Toeieldia Gen. (p. 867.) 



\ Three sessile stigmas Triglochin Gen. (p. 799.) 



f Flowers with a single scale under each set of stamens and pistil. 

 Sheath of the leaves closed round the stem . Sedge Fam. (p. 884.) 

 Flowers enclosed in two or more scales. Sheath of the leaves split 

 open on the side opposite the blade .... Grass Fam. (p. 936.) 

 f Fruit berry. Leaves usually broad .... Arum Fam. (p. 778.) 

 166 <j Fruit a dry nut. Leaves linear and sedge-like. 



[_ Bulrush Fam. (p. 775.) 



II. CRYPTOGAMS. (No stamens or pistil.) 



'"Plants with distinct roots and stems or roots tocks, with leaves or 



green branches 2 



Plants variously shaped, without distinct roots, stems, and leaves, sel- 

 dom green unless aquatic . . . Cellular Cryptogams (p. 1018.) 



"Fructification in terminal spikes 3 



Fructification radical or in the axils of small leaves 4 



Fructification on the back of the leaves or leaf-like branches. 



Fern Fam. (p. 1031.) 

 ^Sterns leafless, jointed, simple, or with whorled branches. 



Equisetum Gen. (p. 1024.) 

 Stems bearing numerous small leaves . . . Clubmoss Gen. (p. 1019.) 

 Stem bearing a simple or branched leaf below the spike. 



Fern Fam. (p. 1031.) 



J Capsules sessile Clubmoss Fam. (p. 1019.) 



\ Capsules stalked 5 



p, f Capsules globular or urn-shaped, opening with a lid . Mosses (p. 1018.) 

 \ Capsules opening in valves Hepatioe (p. 1018.) 



1< 



3<! 



V.— ARRANGEMENT OF THE NATURAL ORDERS IN THE 

 PRESENT WORK. 



The very unequal manner in which the several Natural Orders are represented 

 in the British Isles, renders it impossible, in a work confined to British plants, 

 to give any fair idea of the subclasses into which these Orders have been grouped, 

 or of the principles which have guided the authors of the linear arrangement the 

 most generally followed. The following recapitulation is therefore merely in- 

 tended as a sort of table of contents, showing the order in which the families 

 follow each other in the present work ; at the same time that the attention is 

 called to one or two of the most striking, the most important, or the easiest ob- 

 served features of each one. These characters are however general, not always 

 without exception, and sometimes specially applicable to British genera only. 



CLASS I.— DICOTYLEDONS. 



In the germination of the seed the plumula arises between two (rarely more) 

 lobes or cotyledons of the embryo, or from a terminal notch. 



Subclass 1. Thalamiflores. — Petals distinct from the calyx, and from each 

 other, seldom wanting. Stamens usually hypogynous or nearly so. 



apocarpous, 

 I. Ranunculus family. Petals definite. Stamens indefinite. 



