One of the most important jobs of any plant is to successfully reproduce. Because plants are stationary, they rely on creative techniques to perpetuate their kind. Though seeds, cones and spores have very different functions, they each have a distinctive and vital role in the reproduction of their specific plant species.
Seeds are found in both coniferous and flowering plants. They range widely in size, from tiny, barely visible grains to large, bulbous nodules two inches or more in length. Seeds can be firm and fleshy, rough and woody, or hard and smooth. They can even have spikes or attached tufts of feathery or cottony material.
Cones are the reproductive parts of coniferous trees like pine, fir and cypress. They can be large or small in size, and typically feature overlapping "scales" that start off tightly bound and spread open as the cone matures.
Spores are the reproductive agents of fungi and lower-level, non-flowering plants like ferns and club-mosses. When mature, spores are released en masse into the wind. Their tiny size and lightweight, powdery composition make it easy for them to drift away from their parent plants.
All seeds house a dormant, fertilized plant embryo. Most feature a hard outer shell that protects the embryo from premature germination, extreme weather and predators. Inside the shell, the embryo is surrounded by a thick, starchy matter called the endosperm, which will serve as food for the immature plant.
Seeds lie dormant beneath the soil until they receive the proper amount of warmth, sunlight and moisture, at which time they germinate. A small root, called a radicle, shoots down from the base of the seed, and a shoot sprouts upward. The seedling then matures and grows its first set of true leaves. Once the leaves appear, the plant is able to produce food from sunlight, and no longer needs the endosperm.
Each coniferous tree produces both male and female cones. Male cones are much smaller and less showy than their female counterparts. During spring, pollen produced from the male cones is carried by the wind through the female cones fertilizing their egg cells and prompting them to produce seeds.
Unlike seeds, spores are not fertilized embryos and have no food stores. Instead, they are single or multi-cellular organisms cells that carry copies of their parents' genes. When spore cells land in a suitable place with sufficient warmth and moisture, they begins to divide continuously, eventually growing into a new plant.
One of the oldest viable seeds in the world was that of a date palm found near the Dead Sea during an excavation of King Herod's Palace. Carbon-dating revealed the seed's age to be around 2000 years old, yet the seed sprouted successfully in 2005.
The largest seed cones in the world come from California's Coulter pine. Cones from this tree can grow up to 14 inches long and weigh up to 8 pounds.
Plant Root Parts & Functions
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