PLANT FAMILIES AND HIGHER GROUPS 7 



the specific part of the name. Both parts are required to form the 

 name of the species. Alba, nigra, etc., by themselves are not names. 



11. The authority. It has sometimes happened that different 

 botanists have given different names to plants of the same .species, 

 and the same name to plants of different species. To avoid any un- 

 certainty as to just what plant is meant it is customary in technical 

 botanical writings to place after a specific name the name (usually 

 abbreviated) of the person or persons who first gave to the plant 

 the name adopted. For example, if we write Gypsophila fastigiata L., 

 it is plain to a botanist that the species so called by Linniseus is the 

 one intended. LinniEus in this case is called the authority for the 

 name. In popular or elementary books, like the present, authorities 

 are usually omitted for the reason that only plants well known to 

 botanists are apt to be mentioned, and the authorities for these may 

 readily be found in the more technical botanies in case of need. 



12. Plant families and higher groups. On the same 

 principle that similar .species form a genus, similar genera 

 are grouped into a family; and families w^hich have certain 

 fundamental points of similarity are associated to form still 

 more inclu.sive divisions of the vegetable kingdom. Thus 

 the oaks (Quercus), chestnuts {Castanea), beeches (Fagus), 

 and other trees which agree in having their flowers in tassel- 

 like clusters, and their nut-like fruits held in something corre- 

 sponding to a beech-bur, make up the beech family or Fagacea. 

 The poplars (Populus) and willows (Saliz) which also have 

 tassel-hke fiower-clusters but only small seeds bearing slender 

 silky hairs, constitute the willow family or Salicacece. Lilies 

 and similar plants compose the lily family Liliacece; palms, 

 the palm family, Palniacece; pine-like plants, the pine family, 

 Pinacece, and so on. Plants like cabbage and mustard with 

 flowers of cross-like form belong to the mustard family Cru- 

 ciferce. ' 



So closely similar to the Fagacece are the members of the 

 birch family, Betulacece, that botanists find it convenient 



1 It will be noticed that the botanical name of the families is formed 

 usually Ijy adding the termination acew to the main part of the name of 

 a typical genus of the family. This termination corresponds to the 

 English suffix aceons, meaning "having the qualities or characteristics 

 of." The name is thus of adjective form, the noun planlcc being under- 

 stood. Hence the full name of the willow family would be Plantce 

 salicacecB, meaning salicaceous (or willow-like) plants. In a few cases 

 like Crudjerm (from L. crux, crucis, a cross; fcru, I bear) the name ex- 

 presses a peculiarity of the whole family. 



