SEEDS AND FRUITS
After male pollen grains have been carried to the female parts of a flower, the male and female cells join and begin to develop into the baby plant. The flower parts are no longer needed and they shrivel away, to be replaced by the developing seeds in the seed-head. A seed is usually accompanied by a food store for its early growth, neatly packaged inside a casing. Some plants, like orchids, produce many thousands of tiny seeds. An ear of wheat is a head of wheat seeds or grains. We grind them up to make flour.
Seeds have a better chance of growing if away from the parent plant. If they fall next to the parent, they would be in its shade and would also compete with it for soil nutrients. For these reasons, seeds have many ways of being spread far and wide.
FRUITS AND NUTS
A fruit is the protective case around a seed. Some fruits are very light, like the feathery “parachutes” of the dandelion. They blow away in the wind. Some fall into water and float to a new place, like the coconut. A nut has an especially tough outer case. Animals may crack some nuts and eat the seeds within, but they also drop many as they feed. A squirrel buries nuts such as acorns, but may forget to dig them up, so in effect it has planted new oak trees! Some fruits have juicy, tasty flesh. These are known by the everyday name of “fruits”. The fruity part attracts animals to eat it. The seeds are spilled or pass through the animal’s guts to emerge unharmed and far away.
A seed germinates, or begins to grow, only when conditions are suitable. This usually requires moisture of some kind, the right temperature, and perhaps darkness, which means the seed, is buried in the soil. Some seeds like those of the ironwood tree do not germinate unless they have been scorched by fire. This usually means many plants have burned away so the ground is bare and ready for new life. Other seeds do not germinate until after they have been cracked by frost and then warmed slightly, that is, when winter is over and spring has arrived. When conditions are right, the baby plant begins to grow using its store of food in the seed-leaves, or cotyledons. It splits its case, sends roots down into the soil and grows its shoot up towards the light.
FUNGI
Mushrooms, toadstools, brackets, yeasts, moulds and mildews are all fungi. They form one of the five great groups or kingdoms of living things. Fungi are rotters. They grow networks of thin, pale threads, called hyphae, into the bodies of dead and dying plants and animals. The threads cause the body to decompose. They then absorb the released nutrients through their surface. Like bacteria, fungi are nature’s recyclers. They return the nutrients in dead animal and plant matter or animal droppings back into the soil.
A fungus’s network of threads is known as the mycelium. It is usually hidden in the soil, inside a dead animal’s body or under a dying tree’s bark. So we rarely notice fungi at work. We are more likely to notice them when they reproduce. They do this by growing fruiting bodies. Many of these are shaped like umbrellas—we call them mushrooms and toadstools. The presence of a mushroom indicates a network of hyphae in the soil below, rotting down and absorbing nutrients. The mushroom’s top, or cap, releases millions of tiny fungal spores that blow away in the wind.
Picture Credit : Google