CLASSES, DIVISIONS, AND ORDERS 



BRITISH PLANTS. 



Class I. DICOTYLEDONES'. 



Stems when perennial composed of bark, wood, and pith. 

 The wood furnished with medullary rays and increasing by the 

 addition of concentric layers externally. Leaves usually net- 

 veined. Cotyledons 2 or more, opposite or whorled. — Each 

 floral whorl composed of 6 or 4 parts. 



Division 1. THALAMrFLOB^. Pet. distinct (rarely 0) and 

 as well as the stam. growing separately from the 

 sepals, hypogynoiis 1 



Division 2. OALYCii-i.OB.ffii. Pet. distinct and, as well as 



the stam., perigynous or epigynous 77 



Division 3. CoBOLLirLOEJE. Pet. united, at least at the 



base. Stam. mostly epipetalous 169 



Division 4. Monochxamydb^. Only a single perianth 

 or none ■ • • 



297 



Division 6. GrTMNOSPBEM.s). Ovules and seeds apparently 



naked. Ovary and styles wanting. Perianth wanting. 825 



Division 1. THALAMIFLOEiE. 

 * Apocarpous. 



1. RanurundacecB. Stam. polyandrous (rarely pent- 

 androus). Pistils usually many, of achenes or follicles. — 

 Earely (in Actcea) a many-seeded berrylike carpel 1 



2. Berheridacece. Stam. 6 or 4, opposite the petals; 

 anth. opening by valves from the bottom 15 



1 The characters are drawn to suit our plants. 



