THE FIRST BOOK OF BOTANY. 
EXERCISE XX. 
Color , Surface, Size , Structure . 
Color. —Stems may be spotted, striped, green, 
brown, red, or purple. Surface.— The surface of a 
stem, like that of leaves, may be smooth, rough, shiny, 
dull, hairy, or glabrous. Size.— Stems may be high 
or low, slender or thickened. 
Structure. —To find out the structure of a stem, 
you must break it, and observe first whether it is 
hollow or solid . Next see if it is thready: these 
threads are woody fibers, and, when present, they 
help to make the stem hard and tough. It is then 
called a Woody stem; but, if it is soft and brittle, 
it is an Herbaceous stem. 
The hairs of plants are Arachnoid, when veiy 
long, and loosely entangled, so as to resemble cobweb. 
Bearded, when the hairs are long, and placed in tufts. 
Downy, or Pubescent, when the hairs form a short, 
soft layer, which only partly covers the skin. Hairy, 
when the hairs are rather longer, and more rigid. 
Villous, when very long, very soft, erect, and straight. 
Velvety, short, soft, very dense, but rather rigid, 
forming a surface like velvet. 
There are six questions that you have found it 
very easy to answer about stems. Here they are, put 
together in the form of a stem-schedule. If you can 
remember all these questions, and answer them one 
after another, as the questions of the leaf-schedule are 
answered in leaf-descriptions like that of Fig. 97, on 
page 70, there will be no need of using the schedule. 
But it is very well to use it for a few days, till the 
points to be observed are all fixed in the mind. 
