238 AN INTRODUCTION 
many Species diftinguifhable by the Angles 
of the Stem ; and in Lupinus, the Species are 
not eafy to be known, except by the fame 
Part being Ample or compound. In Eriocau- 
Jon, the moft remarkable Difference is in the 
Culmus, which is guinguangular, hexangular, 
decangular, &c. In Pyrola, fome Speeies are 
diftinguifhed by a triquetrous Scapus. In 
Citrus, the Aurantium is diftinguifhed from 
its Congeners by its Petioles, which are 
winged or increafed by a Membrane on each 
Side ; and’in Gompbrena, there isa Species* 
diftinguifhed by its Peduncles which are Di- 
phyllous, being furnithed with two oppofite 
Folioles that are placed under the Head of 
the Flowers. 
The LE AVES exhibit moft natural and 
alfo moft elegant {pecific Differences. Thefe 
have been fo amply treated off already, that 
it would be only Repetition to particularize 
or exemplify the numerous Cafes that occur 
of fuch DiftinGions. 
FULCRA are generally a good Mark of 
Diftinction, and muft be carefully attended 
to by the Botanift for the Determination of 
the Species; as we fhall thew by many Ex- 
* Gomphrena globofa (Lin. Spec. Plant. 224.) 
8 amples, 
