Dicots (Dicotyledons)

1. Dicots (Dicotyledons) By Nicolle Rodriguez and Daniel Ospina

2. What Makes a Dicot • Dicotyledon, or dicots, are one of the two major classes of angiosperms. • Dicotyledon comes from the word “cotyledon” (the first leaf or pair of leaves of a plant) and the prefix “di-” meaning two. As the name suggests when the seed sprouts there will be a pair of leaves.

3. Examples of Dicots • All flowering trees are dicots and many flowering plants are dicots, too. • Most fruits and vegetables are dicots. • All legumes (beans, peas, etc.) are dicots.

4. Leaves of Dicots • Dicots tend to have leaves that are very different from those of monocots. • The veins in the leaves have a branched pattern, in which a vein parts the center and branches apart. • In monocots, the veins move along parallel to the leaf. • This is not always a reliable way to tell the two apart.

5. Parts of the Flower • The parts of these flowering plants include: petals, stamen, carpel, flower stalk, nectary, receptacle, and the sepal. • Petals: The separate parts of the corolla of a flower. • Stamen: Collective noun for the male parts of the plant. Includes the filament and the Anthers. • Filament: The stalk of the Anther. • Anther: Structure that contains pollen sacs. The pollen is caught by organisms like insects that enter the flower. It is then moved to the ovule. • Carpel: Collective noun for the female parts of the flower. Include the stigma, the style, the ovary, and the ovule. • Stigma: Structure that is covered in a sticky substance that the pollen grains will stick to. • Style: structure that raises stigma away from ovary to prevent contamination.

6. More Parts of a Flower • Ovary: Protects the ovule. After fertilization, this becomes the fruit. • Ovule: Acts much like the egg used in animals and will become the seed after fertilization. • Sepal: Structure that protects the flower while it is still a bud. • Nectary: This is where the sugary nectar solution is kept to attract insects. • Flower Stalk: Elevates and supports the flower. • Receptacle: The flower’s attachment to the stalk. Sometimes becomes part of fruit such as in the case of strawberries.

7. Flower Parts

8. Parts of the Plant • Petiole: The stalk of the leaf. • Midvein: The central vein of a leaf • Margin: The edge of a leaf. • Terminal Bud: Main area of growth in a plant. This is where a flower will grow. • Axillary Bud: A bud that forms at the node. A new branch will grow from here. Sometimes a flower will come out and will be called a floral bud. • Hypocotyl: Forms a connection between the plant and the radicle. • Radicle: The primary root.

9. Flowering Plant Parts

10. Growth and Reproduction • Dicots grow just like monocots. Dicots, however, may have the ability to form woody tissue such as in trees. • The sexual organs in the flower help it to produce seeds and fruits. An insect would pollinate it and move the pollen into the ovule in which the embryo seed would form with its two cotyledon.

11. Number of Flower Parts • If you were to count the number of different floral parts such as petals, a monocot would tend to have a number of floral parts that is a multiple of three (such as having six petals) and dicots would tend to have a number of floral parts that is a multiple of four or five (such as having ten petals). • Like observing the type of leaf the plant has, this is not always reliable.

12. Roots • Dicots usually have a root system in which there is a primary root and multiple roots that branch off of it. These roots are considered fibrous. • Some, like the carrot, have a taproot in which a massive root forms.