NOMENCLATURE OF GENERA AND ORDERS. 407 
the species bears the name of its discoverer or describer, as 
Viola Muhlenbergu, Viola Nuttalli, &e. 
Specific names are written after the generic, as indicated 
above in the different species of the genus Viola, and these 
together constitute the proper appellation of a plant, in the 
same way as the surnames and Christian names designate the 
members of a family. The specific names should also in all 
cases be adjectives, or substantives used adjectively; in the 
former case they should agree in gender and case with the name 
of the genus. Thus when a species is named after its discoverer 
or describer, it is usually placed in the genitive case, as Viola 
Muhlenbergii and V. Nuttallii ; but when such names are merely 
given in honour of botanists who have had nothing to do with 
their discovery or description, the specific names are generally 
put in the adjective form, as Carex Hookeriana, Veronica 
Lindleyana : such a rule is, however, frequently departed from. 
Sometimes the specific name is a noun, in which case it does 
not necessarily agree with the genus in gender; such specific 
names are often old generic ones, as Dictamnus Fraxinella, Rhus 
Cotinus, Lythrum Salicaria, Rhus Coriaria, Dianthus Armeria, 
Rhamnus Frangula. In such cases the specific name should 
begin with a capital letter : a similar rule should also be adopted 
when it is derived from a person ; but in all other instances it is 
better that the specific name should begin with a small letter. 
The specific name was called by Linnzeus the trivial name ; thus, 
in the particular kind of Violet called Viola palustris, Viola is 
the generic, and palustris the specific or trivial name. 
b. Genera.—The names of the genera are substantives, in 
accordance with the rule laid down by Linneus as follows :— 
Every species shall have a particular name, compounded of a 
substantive and an adjective, whereof the former indicates the 
genus, and the latter the species. This has already been re- 
ferred to under the head of Species. The names of the genera 
are derived in various ways : thus, either from the name of some 
eminent botanist, as Linnza after Linnzeus, Smithia after Smith, 
Hookeria after Hooker, Jussizea after Jussieu, Tournefortia after 
Tournefort, Lindleyana after Lindley ; or from some peculiarity 
of structure or habit of the plants comprised in them, and from 
various other circumstances. Thus, Crassula is derived from 
the genus comprising plants with succulent or thickened leaves ; 
Sagittaria, from its arrow-shaped leaves ; Arenaria, from grow- 
ing in sandy places ; Lithospermum, from its fruits (which were 
formerly regarded as seeds) having a stony hardness ; Campa- 
nula, from its corolla being in the form of a bell ; Lactuca, from 
its milky juice ; and so on. Others, again, have derived their 
generic names from supposed medicinal properties, such as Scro- 
phularia, from its former use in scrofula ; Pulmonaria, from its 
employment in pulmonary disease, &c. 
c. Orders.—The names of the orders in the Artificial 
