Learning about the anatomy of a seed
Summer is the best time for eating fresh, just-out-of-the-garden vegetables. Green beans, peas, corn, okra, squash, I could go on and on.
Many of these plants produce seeds that we love.
All plants yield seeds by way of sexual reproduction and this is our second in a series of articles on plants.
A seed is made of a hard outer coating that is for protection. Beneath this coat is the food reserve to feed the embryonic seedling hidden inside.
This is the cotyledon or cotyledons.
There are two groups of plants defined by this seed particulate — the monocotyledons (or monocots) that have only one food reserve, and the dicotyledons (or dicots) that have two reserves.
The embryonic seedling is attached to the cotyledon(s) along with the radicle, or microscopic root.
As water enters the seed, the coat expands and wrinkles to allow air and water to enter and gain access to the seedling.
The radicle immediately begins to grow downward to anchor the plant as it begins to grow.
The cotyledons split and flare out, making room for growth.
The seedling arches upward (like a shepherd’s crook) to push through the soil, then the leaves move up as the cotyledons stay attached to each side of the stem, remaining until all the food energy is used up.
Then they simply fall off. By this stage, the leaves have flared out and the plant can take up water and begin feeding itself.
For monocots the process is the same, except the seedling has only one cotyledon, as well as a protective leaf membrane called coleoptile that encircles the embryonic seedling.
Monocots and dicots have other defining characteristics as well:
MONOCOTS
• Fibrous root system
• Parallel leaf venation
• 3 plant parts, or multiples
• 1 cotyledon
• No woody growth rings
DICOTS
• Tap root with small roots
• Webbed leaf venation
• 4-5 plant parts, or multiples
• 2 cotyledons
• Woody growth rings
Water, the right temperature, light, enriched soil, all make ideal conditions for growth.
Before beginning any garden, there are many conditions to be addressed.
First, read the seed wrapper or look up the plant to see the best conditions for growth. Usually, a garden is planted where the plants can receive at least six to eight hours of full sun.
There is easy access to water.
A soil test is done to make provision for amendments to the soil. Every effort must be made to make ideal conditions so the garden flourishes.
With all these provisions, you are striving for success.
Hughes is an Ohio State University Extension Master Gardener Volunteer in Mahoning County.