Lesson 10 PLANT PARTS

Plant Parts - Flowers

Flowers not only look pretty but, in fact, are important in making seeds. Flowers have some basic parts. The female part is the pistil. The pistil usually is located in the center of the flower and is made up of three parts: the stigma, style, and ovary. The stigma is the sticky knob at the top of the pistil. It is attached to the long, tubelike structure called the style. The style leads to the ovary that contains the female egg cells called ovules.

The male parts are called stamens and usually surround the pistil. The stamen is made up of two parts: the anther and filament. The anther produces pollen (male reproductive cells). The filament holds the anther up.

During the process of fertilization, pollen lands on the stigma, a tube grows down the style and enters the ovary. Male reproductive cells travel down the tube and join with the ovule, fertilizing it. The fertilized ovule becomes the seed, and the ovary becomes the fruit.

Petals are also important parts of the flower, because they help attract pollinators such as bees, butterflies and bats. You can also see tiny green leaf-like parts called sepals at the base of the flower. They help to protect the developing bud.

Plant Parts - Fruit

The fruit is the ripened ovary of a plant containing the seeds. After fertilization, the ovary swells and becomes either fleshy or hard and dry to protect the developing seeds. Many fruits help seeds spread (maple seeds). Many things we call vegetables are really fruits such as tomatoes, cucumbers, and beans.

Every seed is a tiny plant (embryo) with leaves, stems, and root parts waiting for the right things to happen to make it germinate and grow. Seeds are protected by a coat. This coat can be thin or thick and hard. Thin coats don't protect the embryo well. But thick coats can let the embryo survive some tough conditions.

The seed also contains a short-term food supply called the endosperm which is formed at fertilization but is not part of the embryo. It is used by the embryo to help its growth. In the bean that is shown, the endosperm is no longer there. It has been used for the growth of the embryo, and most of its nutrients and energy are now in a different form within the tissues of the cotyledon.

Plants with one cotyledon (like corn) are called monocots. If they have two cotyledons (like beans), they are called dicots.

Seeds are a plant's way of getting from one area to another by either wind, water or animals.

Do you know what all plants need to grow? Detective LePlant has discovered seven things. Click here to learn them! Room to Grow Temperature Light Water Air Nutrients Time Growing Plants Indoors All plants need these seven things to grow: room to grow, the right temperature, light, water, air, nutrients, and time. Room to grow. All plants like to have room to grow. The above ground portions of the plant need space so leaves can expand and carry out the job of making food. Roots also need room to grow. Plants growing in small spaces will have their roots crowded, and that results in smaller amounts of growth. Growing Plants Indoors Temperature Most plants like temperatures that most humans like. Some may like warmer temperatures while others may prefer cooler temperatures for best growth. It is always good to know where plants come from so you can make them feel at home. Most plants like to have cooler temperatures at night and don't like to be in a drafty spot. Growing Plants Indoors Light Plants grown indoors like bright light. Windows facing the south or west have the best light. Try to place the plants close to the window to take advantage of all the light. The further away from the window, the darker it becomes. A plant will tell you when it isn't getting enough light, because its stems will be thin and it will lean toward the light. If you don't have a bright window, try using grow lights. Remember to have the light about six inches above the plants and leave it on for 14-16 hours each day. Growing Plants Indoors Water Water is important in the plant's ability to make and move nutrients. Without water or with too much water, a plant dies. For this reason, watering is an important part of plant care. Most plants like to be watered when the soil is slightly dry to the touch. When watering, moisten the soil by using enough water so that it starts to come out of the hole in the bottom of the container. (This is why it is important to use containers with drainage holes.) How often you water depends on a lot of things. Plant size, time of the year, and type of plant are a few. Your best guide, though, is to feel the soil. If you stick your finger one inch into the soil and it is dry, then water your plant. Growing Plants Indoors Air Plants use carbon dioxide in the air and return oxygen. Smoke, gases, and other air pollutants can damage plants. Growing Plants Indoors Nutrients Most of the nutrients that a plant needs are dissolved in water and then taken up by the plant through its roots. Fertilizers will help to keep the soil supplied with nutrients a plant needs. Don't apply too much too often. Fertilizer won't solve all of your plant problems, so make sure your plants have good light, good soil, and good drainage. The three most important nutrients are nitrogen,phosphorous, and potassium. Nitrogen is used for above ground growth. This is what gives plants a dark green color. Phosphorous helps plant cell division. It aids in flower and seed production and in the development of a strong root system. Potassium helps fight off disease and provides for strong stems. Growing Plants Indoors Time It takes time to grow and care for plants. Some plants require more time to grow than others. Getting plants to flower or fruit at a certain time can be challenging. Plants that normally grow outdoors need a certain number of days to flower or fruit. You can time plants to flower or fruit on a certain date. This is a good lesson in both plant science and math.