Stipules are small appendages that grow at the base of a plant’s leaves where they attach to the stem. They come in a variety of shapes, sizes, and colors and can be either persistent, meaning they stay attached to the plant throughout its life, or deciduous, meaning they fall off after a certain period of growth.
One of the most well-known types of stipule is the leafy stipule, which looks like a small leaf attached to the base of the true leaf. In some plants, such as pea and bean plants, the stipules are large and can even be mistaken for leaves. Other types of stipules include uni-nerved stipules, which have a single vein running through them, and glandular stipules, which have small glands that secrete fluids.
While stipules are often overlooked, they serve important functions in plant growth and development. One of the most important functions of stipules is to protect the young bud before it emerges from the stem. Stipules can also help to reduce water loss in plants by forming a small protective layer around the emerging leaf.
In some species, stipules can play a role in photosynthesis by performing a similar function to the leaves of a plant. The leafy stipules found in plants such as beans and peas are an example of this. In other species, stipules can be involved in protecting the plant from harmful herbivores or insects.
Stipules can also serve as a way of identifying different plant species. Plant taxonomists often use the shape and size of stipules to distinguish between different plant families. For example, members of the rose family often have stipules that are small, scale-like structures while members of the legume family often have large leafy stipules.
In conclusion, while stipules may not always catch our attention, they serve important functions in plant growth and development. Understanding the morphology and function of these often-overlooked structures can help us better appreciate the complexity of plant anatomy and the role it plays in the natural world.#16#