Even in the seaweeds, which may seem to have stems, you will find that
such is not really the case. They have generally a flat body, which is
thin at the edges, with a stronger mid-rib, and the flat edges get worn
away in the older parts of the plant, and so leave the mid-rib looking
like a stem, though it is not so really (~see~ fig. 134).
[Illustration: Fig. 134. A Seaweed, showing the branched body, which is
not divided into stem and leaves.]
When we come to look for flowers or even spore capsules, we see still
more clearly how simple these plants are; they have not nearly such a
complicated history as the moss. For example, in the toadstools we find
that there are many spores formed directly on its lower surface, on the
“gills,” and these grow out to form new toadstool plants. You can see
the spores if you cut off a toadstool or mushroom head which looks full
grown and is quite expanded, and then lay it on a sheet of gummed paper
over-night, with the gills downwards, and another beside it with the
gills up. Next day you will find that the paper under the one where the
gills were downwards is covered with radiating lines of spores, just as
they fell from the gills, and repeating their pattern.
[Illustration: Fig. 135. Part of a Bladder-wrack, showing the floats
(~f~) and special swollen tips (~s~).]
The seaweeds have the most complicated way of forming spores of any
of this family. There are special little swellings at the ends of the
plant, as in the ordinary bladder-wrack, for example (fig. 135 (~s~)),
and in these are formed the cells which will give rise to new plants.
The other simple bladders (fig. 135 (~f~)) are only full of air, and
act as floats to keep the plant up in the water.
In this the simplest family of all, we find more variety in the
appearance of its members than in any of the others, so that it may
seem to be rather difficult to recognise the plants which belong to
it. Perhaps the easiest way of settling this, is to see if the plant
fits into any of the other families, and if it never has flowers nor
cones, neither fern spore-capsules nor the big spore-capsules of the
moss family, then you are fairly safe in classing it with the simplest
plants.
Very many of the plants of this family are found living in water, which
is perhaps one of the reasons that they can afford to be so simple,
because the water protects them from many of the dangers land-plants
have to prepare against, such as wind, drought, or too much sunshine.
This is the simplest family of real, undoubted plants; but there is
one class still simpler, and that is the family of ~bacteria~, about
which you must have heard much, as many of them cause our diseases,
though others do much valuable work for us. All the same, we will leave
these little creatures alone, and content ourselves with the five great
families of plants which we can see with our own eyes.
[Illustration: PLATE IV.
A LOW EDGE OVERGROWN WITH FOXGLOVES AND MANY OTHER WILD PLANTS]
Public-domain text, read in full here on John Shaqi.
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