Principles of Classification* SI 
either simple or compound, as it supports one or more 
leaves. 
Frons, or frond, is a term applied to the leaves of 
ferns, in which the stem, leaf, and parts of fructifica- 
tion are united. 
Stijjes, or stipe, is the term applied to the stem of a 
frond, and to the stalk of a mushroom ; the stipes in 
ferns is commonly scaly. 
Leaves. — In the description of plants, and particu- 
larly in the discrimination of species, the forms of leaves 
afford obvious characters, and therefore merit particu- 
lar attention. Leaves are properly distinguished into 
simple and compound : But their forms will be readily 
understood by the references to the plates. 
Roots. — Roots sometimes afford specific names to 
plants, so that their forms and diversities require atten- 
tion in descriptions. 
A fibrous root, radix fibrosa^ is the simplest kind, and 
is composed of fibres which are either undivided or 
branched. This kind of root is peculiar to many 
grasses, and to most annual plants. 
A creeping root, radix repens , is considered as a 
kind of underground stem, which shoots out horizon- 
tally, and throws off fibres in its course. Couch-grass, 
and the common bent on sand-hills near the sea, are 
excellent examples of this kind of root, to which may 
be added common mint. 
A fusiform, or spindle-shaped root, radix Jusiformis 3 
is of a tapering form, and penetrates perpendicularly 
into the ground, as in the carrot, the parsnip, and ra- 
dish. 
An abrupt root, radix prcemorsa 3 has somewhat of a 
