This time we are going to talk about the taxonomy and morphology of coffee. If we talk about plants, it is very likely that the coffee plant is neither the first nor the second that comes to mind. In fact, it’s probably not even in your top 10 choices.
However, the coffee plant is one of the most famous and cultivated plants in the world, with very diverse characteristics and variations.
Therefore, in this article we are going to cover in as much detail as possible everything that makes up the coffee plant. From the most general, as is the plant itself, to each of its parts: the root, the stem, the leaves and the fruit.
The coffee tree or coffee plant
The coffee plant comes from the Rubiaceae family and belongs to the Coffea genus. Rubiaceae are easily identifiable, mainly, by five distinctive traits:
- Their leaves grow in pairs
- The leaves have no divisions
- The edges of the leaves are smooth
- The flowers are hermaphrodite
- Each fruit has two seeds
You may also be interested to know all about the origin and history of this famous infusion that we know as coffee.
The coffee tree is a small tree -or shrub- with the characteristic of being evergreen, that is to say, evergreen. This means that its leaves remain alive throughout the year, as opposed to trees whose leaves die when they reach a certain season, for example, autumn.
The coffee plant can reach a height of ten meters in the wild, but it is usually kept at a smaller size in cultivation, close to three meters. This plant flowers only in its third or fourth year.
Depending on the species, the fruits of the coffee plant have different capacities. While the fruits of the Arabica can self-fertilize, the fruits of the Robusta need pollination by insects. These are the most commercially important species of coffee plants: Arabica and Robusta.
The fruit of the coffee plant involves 15 weeks of development after the plant flowers. The endosperm, that is, the source of nutrients in the fruit, begins its development after twenty weeks and, for a few months, accumulates solid matter and attracts the energy generated by photosynthesis.
Next, we will see in detail each one of the parts of the coffee tree or coffee plant.
The coffee plant has intricate roots at the bottom of the stem, a few centimeters deep. Among this complex structure is the main root: a longer, thicker root that runs vertically from the end of the stem to the end of the root.
This root, which supports the other smaller roots, can reach 50 centimeters if the plants are more than 5 years old.
On the other hand, the secondary roots or ramifications are those in charge of absorbing nutrients and water from the soil.
Since we are talking about the morphology and taxonomy of coffee, it is worth mentioning that only the root can be divided into eleven different parts: Xylem, Phloem, Pericycle, Endodermis, Parenchyma, Epidermis, Protodermis, Meristem, Calyptra.
While all parts of plants are important to a greater or lesser extent, there is one crucial element in all of them: yes, how did you know? The stem.
The stem of the coffee plant serves to support both the branches and the roots. The stem, like the roots, can also be divided into several parts: nodes, branches, terminal bud, auxiliary bud and internodes.
We can imagine the stem as a pipe that runs water and nutrients through the stem to the root, all the way through the plant.
The nodes of the stem, on the other hand, have the task of starting the process of growing new branches. For the duration of this process, the nodes must hold the branch in place and keep them rigid.
On the other hand, the terminal bud is, as its name suggests, the one that marks the end of the stem and the beginning of new growth. The terminal bud is in charge of the development of new branches throughout the life of the plant.
The leaves of the coffee plant, like its fruits, change color depending on the stage they are in. At the beginning, they are light green, but then that tone darkens over time.
Although it may sound strange, the leaves of the coffee plant are crucial for its survival. This is because it is the leaves that form the plant and give it its structure.
To know as completely as possible the morphology and taxonomy of coffee, it is important to know the 5 parts that make up the leaf of the coffee plant: limbo, central nerve, petiole, stipula and margin.
They are small green protuberances that are found at the beginning of the leaf. The stipules are what protect the base of the leaf and, in turn, indicate the place where the bud was.
The petiole is a thin stalk that connects the leaves to the branches.
3. Central nerve
The central nerve resembles human veins: it is a structure in charge of transporting nutrients.
4. The margin
As you might expect, the margin is the edge of the leaf.
5. Leaf blade
The leaf blade is everything green on the leaf. This is the area where photosynthesis takes place. Photosynthesis is the name for the process that converts sunlight into energy.
4. The coffee fruit
The coffee fruit is the element that remains for us to fully understand the morphology of coffee. For the coffee plant, the fruit is its guarantee of survival and reproduction.
Inside these fruits there are two seeds united by the parchment: a transparent membrane of natural composition, which is what gives it its sweet taste. Each seed, in turn, has a nucleus that carries the embryo and is responsible for the development of the plant.
This fruit has a protective layer called pulp, which is the fleshy part of any fruit. The pulp is in charge of protecting the seed from external factors.
On the other side, in the visible part of the seed, is located what is known as skin or epicaris. The skin or epicaris is in charge of protecting the fruit from bacteria and other biological factors.
Inside the fruit we can also point out the thick skin that covers the seed. This is the epidermis, in charge of protecting the seed of the fruit from, for example, the gastric juices of animals that eat it.
This has the objective of preserving the genetics of the plant once the ingested seed is expelled from the animal.