Parts of a flower
Flowers can be unisexual, having only male or female parts, or bisexual, having both types of parts. The male parts of a flower make up the stamens. The entire whorl of stamens in the flower is called the androecium.
The sac-like structures at the top of the stamen are the anthers. The anthers house pollen, which contain the male gametophytes that make the sperm. The thread-like stalks that lift the anthers up are called filaments.
The female parts of the flower make up the pistils. The entire whorl of pistils in the flower, which may be separate or fused together, is called the gynoecium.
The sticky tips at the top of the pistils that receive pollen are called stigmas. The swollen bases of the pistils are the ovaries. Inside the ovaries are tiny pearl-like structures called ovules. The ovules contain the female gametophytes, which make the eggs. The slender stalks that connect each stigma to an ovary are called styles.
Types of plant tissues
Plant tissues come in several forms: vascular, epidermal, ground, and meristematic. Each type of tissue consists of different types of cells, has different functions, and is located in different places.
| Tissue | Cell Types | Function | Locations |
|---|---|---|---|
| Vascular tissue | Xylem is made up of vessels and tracheids Phloem is made up of sieve cells and companion cells |
Xylem transports water Phloem transports sugars |
In stems, leaves, and roots |
| Epidermal tissue | Parenchyma | Protect plant tissues and prevent water loss | Outer layer of stems, roots, and leaves |
| Ground tissue | Parenchyma Collenchyma Sclerenchyma |
Makes up bulk of plant mass | Stems, roots, leaves |
| Meristematic tissue | Parenchyma | Divide to produce new growth | Tips of shoots Tips of roots In buds In a ring around the stem in woody plants |
Monocots vs. dicots
Botanists used to sort the flowering plants into two main groups, the monocots and the dicots. Although we know now that the evolutionary history of angiosperms is more complicated than this system suggests, these two categories are still useful for helping botanists identify plants and get quick insight into some of their important growth characteristics. In the table below, I highlight some of the traits that are typically associated with plants in these two groups.
| Monocots | Dicots | |
|---|---|---|
| Veins in leaves | Parallel venation | Netlike venation |
| Flower parts | Parts in multiples of 3 | Parts in multiples of 4 or 5 |
| Roots | Fibrous roots | Tap root or branching roots |
| Seeds | One cotyledon | Two cotyledons |
| Vascular bundles | Scattered around the stem | In a ring around the stem |