Plants have different parts. The roots, stem, shoot, leaves and flowers. In evolutionary process they grow and adapt in different environment to act specifically. The part that attaches leaves to the stem is called petiole. The main difference between phyllode and phylloclade is, phyllode is a modified petiole or a shoot that connects the stem with leaf. It resembles the function of leaf. While phylloclade is a modified stem, that is responsible for photosynthesis. It also acts like a leaf.
What is Phyllode?
Phyllode is a petiole or shoot or rachis that due to environmental changes has modified itself into a leaf like structure to perform the photosynthesis. Instead of having a broad base or having irregularly arranged vascular bundles it has modified itself into a leaf. In most cases, the lamina is reduced or absent and Phyllode takes on function of leaf. The structure of leaves that it is modified into is bipinnate. Bipinnate means it has many leaflets that are further subdivided in a pinnate fashion. The leaflets of this shoot falls early. Phyllode is formed as a result of xerophytic adaptation to reduce transpiration from leaves. It is not succulent and does not bear a flower. It subtends a bud. Vertically expanded petioles are seen in a number of acacia specie. The leaves of many monocotyledons are usually Phyllode in origin. In Parkinsonia aculeate, the rachis is enlarged and persists after the leaflets abscise. Phyllode becomes the mail photosynthesis organ.
What is Phylloclade?
Phylloclade or cladode is a modified photosynthesis organ, instead of a flat green leaf it is a flat green stem that plays the role. The cladodes are similar looking to leaves. The phylloclades are scaly and small suspended by a leaf. These are short lived and soon get cut-off. Specie called tape worm plant has horizontal lines over it. It has axillary buds where there flower rises. Here the stem is modified into thick flattened leaf which is the main organ that photosynthesizes. As it is thick the middle portion does not receive enough radiation. To that modified stomata are present at both the flattened ends of leaves which allow enough carbon dioxide to travel in between. The modified flattened stems are fixed structures that cannot be reversed once changed. It is seen in some xerophytic plants. It may be flattened or cylindrical. Opuntia and Casuarina are its examples.
Key Differences between Phyllode and Phylloclade
- Phyllode is a modified leaf, a petiole, while phylloclade is a modified stem.
- In Phyllode petiole is changed to a planed, leaf like structure green in colour showing photosynthesis while in phylloclade stem is reformed into flat, green leafy structure to photosynthesize.
- Phyllode bears an axillary bud while phylloclade does not.
- Phyllode flower or bud are absent while in phylloclade it is present.
- Phyllode does not branch while phylloclade does.
- In Phyllode spines are absent and in phylloclade it is present as axillary buds.
- Scaly leaves are absent in Phyllode while it is present in phylloclade.
- In Phyllode node and internodes are absent while are present in phylloclade.
- Example of Phyllode is Melanoxylone and Acacia while phylloclade is Cactus and Cocoloba.