BOTANICA* 
29 
parts of the surface, which is an essential difference from 
bulbous knobs, where they are confined to the caudex of the 
bulb only, and are the true and genuine roots; the bulb itself 
being only a large bud under ground. 
Ra dlcula (alittle root) is the stringy or fibrous part of the 
root, descending from the caudex; and is really the principal 
and essential part of every root, and by which the nourish¬ 
ment is drawn from the earth for the support of the plant. 
II. The TRUNK, which includes the branches, is that part 
which rises immediately from the caudex, and produeeth the 
leaves, flowers, and fruit. It is either herbaceous, shrubby, 
or arborescent; and is generally covered with an outer and an 
inner bark ;* and is distinguished according to its shape, 
substance, surface, &c. and admits of the following sorts, 
(viz.) cautis , culmus,scapus, stipes. 
1st. Caul is (a stalk or stem) is the main or universal 
trunk, which elevates the leaves, and fructification, and is 
applied to /fees, shrubs, and herbs : It is either simple or 
compound; simple, when it doth not divide; compound,, 
when it is divided into branches, 
<2d. Culmus (a straw or haulm) is the proper trunk of 
grasses; and also elevates both the leaves and fructification: 
it is sometimes jointed, and sometimes not; it is also some¬ 
times round, and sometimes angular.—See the class and order 
triandria digynia. 
* The outer bark either runs longitudinally, as jn oak, ash, &e. and in most 
other trees; or transversely, as in cherry, birch, &c. if transverse bark is put into 
the fire, it shrivels up, and burns like parchment or leather ; but in those trees 
where the outer bark runs tjansversely, the inner, or principal bark runs longitudi¬ 
nally ; several other trees than above mentioned have a transverse cuticle, but in a 
less perfect manner.—Many trees have what is calleji the sap (alburnum) which 
lies between the more solid woody part and the bark, as oak * jir, &c.; and the sap 
juice is said to answer the same purpose to vegetables, as the chyle to animals; 
affording nourishment by sanguification and secretion ; and in those trees that have 
not an apparent alburnum, as ash , &c.; the inner bark, though less indurated, is 
supposed to answer the same purpose, as it contains much mucilaginous or 
nutritious matter. Phytologia , p. 492 -^ 1 s 7 . 
