ENTROPOLIA
CHAPTER EIGHT: ENTROPOLIA'S LAND PLANTS
All plants on Entropolia originated in the
sea around 1 billion years ago. Their subsequent evolution is
revealed in fossils and the groups of plants that dominate the
world today. The photosynthesis machinery of Lumers evolved into
a wide range of single-celled and multicellular aquatic plants.
By around 400 million
years ago, the previously bare land surfaces of the planet were
inhabited by one type that was not entirely aquatic. It seems
that the evolution stems from a plant found in the inter-tidal
zone. This area is regularly covered and uncovered by the tides.
It is around this time that ocean levels slowly declined 2 feet
exposing marine life to the planets atmosphere and bare land.
Many of the plants died however the Sprogytes survived by means
of primitive root-like structures, called zoids, for absorbing
water beneath the surface. The tips of upright stalks on its upper
surface carried spores which, when dispersed, grew into new plants.
From the Sprogytes evolved the Croksenia, which had xylem vessels,
hollow tubes made from cellulose and lignin. These vessels provided
both an internal support system that allowed the plant to grow
vertically and a means for transporting water absorbed from the
soil to all parts of the plant. Overtime the Croksenia adapted
by acquiring a thickened layer of cells covering the whole plant.
This cut down water loss by evaporation. These adaptations opened
up the evolutionary options for a staggering diversity of terrestrial
plants.
Plants began to colonize
the muddy fringes of coastal swamps and became more complex than
the plants found in the ocean. These new plant forms were marked
by the fact that they had within them systems of minute tubes
or vessels, they were vascular. These vessels carried water and
nutrients from the soil and the products of photosynthesis around
the plant. With this transport system, plants were endowed with
the possibilities for becoming more complex anatomically, with
parts designed for different functions, leaves for photosynthesis,
stems for support, and roots for anchorage and absorbing water
and minerals.
Land plants became increasingly diverse and began to grow in
drier, fully terrestrial environments as well as swamps.
One of the more interesting plants to evolve is the Endron.
These plants are interesting because of the height that they have
been known to grow to. It seems that this plant is the beginning
of what is known on Earth as trees. Endrons grow to heights of
30 feet and have an intrigue root system to keep it from falling
over. The Endron is able to survive due to the development of
vascular bundles. These clusters of microscopic tubes develop
from cylindrical cells placed end to end. One set of tubes, the
xylem vessels, are wide-bore ducts made of tough and flexible
cellulose. They carry water and mineral salts from the roots to
the rest of the plant. 
Surrounding xylem
vessels are phloem vessels which carry sugar and nutrients from
the leaves to the other parts of the plant. The Endron reproduces
by means of cones that hang from the branches of the plant. The
reproductive parts are in the cones. The Endron has two kinds
of cones. The poolen, or male, cone is the smaller and softer
of the two. Seed, or female, cones are larger and harder. The
scales on the pollen cone have tiny sporangia that produce spores.
These spores develop into pollen grains. Each of the scales that
make up a seed cone has two ovules on its surface. Every ovule
produces a spore that grows into a female gametophyte. This tiny
plant produces egg cells. The wind carries pollen grains from
the pollen cone to the seed cone. A pollen grain sticks to an
adhesive substance near an ovule and begins to form a pollen tube.
Two sperm cells develop in the tube. After the pollen reaches
the ovule, the sperm cell disintegrates. The ovule develops into
a Sporphyte embryo and then into a seed. The seed falls to the
ground and, if conditions are favorable, grows into a new sporophyte.
Another interesting plant to emerge on Entropolia
can be found in the desert region. The Saguaro plants do not grow
close together. By being spread out, each plant can get water
and minerals from a large area. The roots extend over large areas
and capture as much rain water as possible. All other plants on
the planet produce food in their leaves, and the leaves give off
water. However, this plant has no leaves in order to better old
its moisture. Instead stems have taken over the task of making
food for the plant. These stems can also store water. It protects
itself with sharp bristles and spines. The plant produces a small
seeded fruit. Animals eat the fruit thereby carrying the seed
to other locations to grow.