What is the Difference Between Phyllode Phylloclade and Cladode

The main difference between phyllode, phylloclade, and cladode is that phyllode is a modified leaf bearing an axillary bud; phylloclade is a modified stem responsible for photosynthesis, whereas cladode is a modified stem appearing like leaves. 

Phyllode, phylloclade, and cladode are three leaves with different origins. They undergo photosynthesis. 

Key Areas Covered

1. What is Phyllode
– Definition, Structure, Function
2. What is Phylloclade
– Definition, Structure, Function
3. What is Cladode
– Definition, Structure, Function
3. Similarities Between Phyllode Phylloclade and Cladode
– Outline of Common Features
4. Difference Between Phyllode Phylloclade and Cladode
– Comparison of Key Differences

Key Terms 

Cladode, Phylloclade, Phyllode

What is Phyllode

Phyllode is the modified petiole and stems that serve as a leaf in appearance and function. Some plants contain flattened and widened stems or petioles in leaves. In other plants, modified petioles become reduced or vanished. However, the primary function of the phyllode is to serve as a leaf. For example, Euphorbia royleana contains a cylindrical phyllode, and Opuntia contains a flattened phyllode. On the other hand, the genus Acacia has phyllode leaves.

Figure 1: Phyllode

Furthermore, younger plants contain partially formed phyllodes that bear reduced leaves.    

What is Phylloclade

Phylloclade is flattened, photosynthetic shoots with modified branches. The genus Phyllocladus contains celery pines, a small genus of conifers in the family Podocarpaceae. This genus occurs in Tasmania, New Zealand, and Malesia in the Southern Hemisphere. However, P. hypophyllus occurs in the Philippines, a short way north of the equator. Also, this genus contains small to medium-sized trees that are shrubs, sometimes reaching 10-30 meters in height.

Figure 2: Phylloclade

Additionally, the leaves of this genus are tiny, sparse, scale-like, and 2-3 mm long. Further, leaves can be photosynthetic for a short period and then become brown soon. 

What is Cladode

Cladode is a photosynthetic leaf made up of a modified green stem. Significantly, the cladode leaves are photosynthetic and resemble leaf-like branches. However, cladode leaves greatly resemble and perform like leaves. Sometimes, phylloclade leaves are considered a type of cladode leaves. Some Asparagus species and Butcher’s broom (Ruscus aculeatus) contain cladode leaves.

Figure 3: Cladode

Moreover, the two main characteristics of cladode leaves are limited growth and one or two internodes. Also, most of the leaf-like structures are cladode. 

Similarities Between Phyllode Phylloclade and Cladode

• Phyllode, phylloclade, and cladode are three types of modified leaves that can occur in plants.
• They undergo photosynthesis. 

Difference Between Phyllode Phylloclade and Cladode

Definition

Phyllode refers to a flat expanded petiole that replaces the blade of a foliage leaf, fulfills the same functions, and is analogous to a cladophyll. Phylloclade refers to a flattened stem or branch (such as a cactus joint) that functions as a leaf. Meanwhile, cladode refers to shoot systems in which leaves do not develop; instead, the stems become flattened and assume the photosynthetic functions of the plant.

Type

Phyllode is a modified leaf, phylloclade is a modified stem, while cladode is a modified green stem. 

Function

Phyllode serves as a leaf; phylloclade is vital in food preparation and storage, while cladode is the main photosynthetic organ.

Examples

Euphorbia royleana and Opuntia are examples of phyllode, the genus of Phyllocladus is an example of phylloclade, while Asparagus species and Butcher’s broom (Ruscus aculeatus) are examples of cladode species. 

Conclusion

In brief, phyllode, phylloclade, and cladode are three modified leaves that undergo photosynthesis. Phyllode is the modified leaf that undergoes photosynthesis. In this leaf, the petiole is replaced by a foliage leaf. Euphorbia royleana and Opuntia are examples of phyllode. In a phylloclade leaf, the stem is modified into a leaf. Their function is to undergo photosynthesis and storage of food. The genus of Phyllocladus is an example of a phylloclade. In comparison, cladode is the modified green stem that undergoes photosynthesis. Asparagus species and Butcher’s broom (Ruscus aculeatus) are examples of cladode species. Therefore, the structure and function are the main differences between phyllode, phylloclade, and cladode.  

References:

1. Wikimedia Foundation. (2022a, March 11). Phyllode. Wikipedia. 
2. Wikimedia Foundation. (2022a, March 11). Phylloclade. Wikipedia.  

Image Courtesy:

1. “Acacia koa with phyllode between the branch and the compound leaves” By Wmpearl – Own work (Public Domain) via Commons Wikimedia
2. “Opuntia cochenillifera (Family Cactaceae) – Phylloclades” By Juan Carlos Fonseca Mata – Own Work (CC-BY SA 4.0) via Commons Wikimedia
3. “Knee Holly or Butcher’s Broom Cladode and flower (Ruscus aculeatus)” By Rosser1954 – Own Work (CC-BY SA 4.0) via Commons Wikimedia