STEM AND LEAVES 121 
Tue Stem.—Stems may be Subterranean (under- 
ground) or Aerial. Underground stems form Rhi- 
zomes, or root-stocks, which send rootlets down- 
wards and buds upwards. Examples: Anemone, 
Bog-bean, Iris. 'Tubers and bulbs are really under- 
ground stems, although they are often spoken of as 
roots, and have been referred to under “ ‘The Root.”’ 
Aerial stems, as their name tells us, are those which 
grow above-ground. 
Aerial stems are simple when they are without 
branches. Example: Grass of Parnassus. They 
are compound when branched. Examples: Knap- 
weed, Flax Seed. The shapes of stems appear when 
they are cut crossways. They may be round, semi- 
round, triangular, square, and in other forms. Stems 
may be: 
1. Hrect.—That is, perpendicular, upright. Ex- 
ample: Foxglove. — 
2. Ascending.—Horizontal when they first leave 
the root, but shortly becoming erect. Example : 
Dog-violet. ; 
3. Creeping.—Stems which run along the ground 
and send rootlets down from joints. Example : The 
“runners” of the Strawberry. 
4. Prostrate.—Lying on the ground, but not root- 
ing. Hxample: Barren Strawberry. 
Lraves.—The flat green part of a leaf is called the 
blade, or lamina. The stalk which bears the leaf 
is the petiole. The extension of the petiole into the 
blade and through to the tip or apex, is the midrib. 
Leaves have veins. When the veins run side by side 
from base to apex, the leaf is called parallel-veined ; 
when the veins branch from the midrib and form a 
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