270 PART IV. VEGETABLE TAXONOMY. 



The publication, however, to be authoritative, must be accom- 

 panied by an accurate description of the plant. Of course, it 

 has very often happened in the history of the science, that sev- 

 eral different botanists have investigated and named the same 

 plant, and the question which name should be adopted is some- 

 times a difficult one to determine ; some authors will perhaps 

 adopt one name, and others another. To save confusion, in des- 

 criptive works it is customary to indicate, usually in abbrevia- 

 tion, the authority for the name. For example, Veronica Anagal- 

 lis, L., Ledum glanduiosum, Nutt., and Mertensia lanceolata, D. C, 

 the abbreviations standing for Linnaeus, Nuttall and De Can- 

 dolle, respectively. 



The names applied to groups of plants higher than genus, 

 have the adjective form, and qualify the word Planter under- 

 stood ; for example, Angiosperma (meaning plantae angiospermae, 

 or angiospermous plants), is applied to one of the main divisions 

 of flowering-plants, and Rosacece (meaning plantae rosaceae, or 

 rosaceous plants), is applied to the natural order, which includes 

 the Roses, Brambles, Pear tribe, etc. They begin with a capital, 

 and terminate usually in ce, ece or acece. 



Names applied to families are commonly made to terminate 

 in acece, as for example, the names, Rosacece, Valerianaceoz, 

 Rubiaceoz, Caryophyllacece and Cucurbitaceoz ; but the names 

 Composite^, Labiates and Leguminosoz, are exceptions. Tribal and 

 sub-tribal names are usually made to terminate in ece, but cus- 

 tom differs somewhat in this regard, and this, as well as the 

 termination a;, are often applied to groups of higher rank. 



Principal Groups of Plants. We shall treat of the plant 

 sub-kingdom under four great divisions, called Series or Branches. 

 These are the 



Thallophyta, 



Bryophyta, 



Pieridophyta, and 



Spermaphyta or Phanerogamia. 



It cannot be claimed that this is a strictly natural classifica- 

 tion ; probably in the present state of our knowledge it is not 

 possible to make one which accurately represents the relations 

 of the lower forms of plant life. The future progress of the 

 science will probably show that the Thallophyta include several 



