TO BOTANY. ~ 237 
guifhed with Certainty, referving the Va- 
rieties fot the Chapter following. ) 
The ROOT often affords a real fpecific 
Difference *, and is fometimes the chief Dif- 
tinction; as in Sci/la, where the Species are 
{carce to be diftinguithed, but by the Bulbs 
being tunicate, folid, or fyuamofe; and in Or- 
chis, where the Species are known by the 
Roots being férofe, round, or te/ficulate ; but 
as Accefs cannot always be conveniently had 
to this Part of the Plant, it is better to fix 
the fpecific Diftin@tion on fome other Cir- 
cumftance, if the Cafe will admit of it. 
The TRUNK often furnithes a fure 
Mark of Diftin@tion. Thus in Hypfericumt, 
Convallariat, and Hedyfarum ||, there are 
* In Fumaria bulbofa, the greater and lefs Sorts with 
a hollow Root, and the greater and lefs Sorts with a Root 
not hollow, appear by the whole Habit of the Plants 
to be Varieties only, as will be obferved in the next 
Chapter. 
+ Hypericum hirfutum (Lin. Spec. Plant. 786. )caule te- 
reti. Hypericum perforatum (Lin. Spec. Plant. 785.) caule 
ancipiti. Hypericum quadrangulum ( Lin. Spec. Plant. 78 5:) 
caule quadrangulo. 
+ Convallaria po'ygonatum (Lin. Spec. Plant. 355.) caule 
ancipiti. Convallaria multiflora (Lin. Spec. Plant. 915¢) 
caule tereti, 
{| Hedyfarum triquetrum (Lin. Spec. Plant. 746.) caule 
triquetro. 
many 
