ber.]

[Illustration: _Poison Ivy_--Can be distinguished from the harmless
woodbine by its three-lobed leaves.]

{120 continued}

The agencies which serve to spread plants about over the earth's
surface are very varied and interesting. Nature has provided seeds
with many appendages which assist in their dispersal. Some seeds have
wings, and some parachutes to take advantage of the wind. Some seeds
are provided with hooks and stickers by which they become attached to
the fur of animals and are in this way enabled to steal a free ride.
Other seeds are provided with edible coverings which attract birds,
but the seeds themselves are hard and not digestible; the fruit is
eaten and the seeds rejected and so plants are scattered. Besides
these methods of perpetuation and dispersal, some plants are
perpetuated as well as dispersed by vegetative reproduction, i. e., by
cuttings as in the case of willows; by runners as in the case of the
strawberry; and by stolons as with the black raspberry. (For further
information on this point see Bailey's "Lessons with Plants.")

Some plant characteristics, however, of greatest interest to the scout
may be enumerated. Plants not only mark zones, but they indicate soils
with certain characteristics, and the crop wise say that the soil on
which chestnut abounds is suitable for buckwheat or peaches. Plants
also indicate the influence of local conditions such as lakes, ponds,
or even variations in contour. A knowledge of the local flora of a
region will at once tell one whether he is upon a northern or a
southern hillside by the plants of the area. The creek bottom will
{121} abound with species not to be found on the hillsides, but species
common to both plain and mountain will mark the progress of the season
up the slope.

In the north temperate zone the moss if any will be found growing upon
the north side of the tree trunk. Each hundred feet of elevation in a
given latitude makes from one to two days difference in time of
blooming of plants. The character of the vegetation of a region is an
index to its climate. Certain plants are adapted to frigid regions,
others to temperate, and still others to tropical areas. Some plants
are adapted to humid sections, while others are admirably adjusted to
desert conditions. A knowledge of these differences in plants will be
of the greatest value to the scout, and if this is supplemented by
information about the value and uses of the various pl