What is the perianth of a flower?

Image - Wikimedia / Pedro Sánchez

Flowers are quite complex structures. They seem very simple to us, but if we stop for a moment to look at each of its parts, we will realize that reality, again, surpasses fiction.

One of those parts that usually have many flowers is the perianth, and it is the one that humans are so attracted to, because it is the one that helps us the most to decide on one plant or another.

What is the perianth?

The perianth it is an envelope that surrounds and protects the sexual organs of the flower. It is sterile, but that does not mean that it does not fulfill an essential role in the reproduction of the plant. In fact, many pollinators are guided by the colors and / or shapes of the perianth to carry the pollen to the stigma, from where it will pass to the ovary and from there to the ovule.

It is made up of two pieces:

Corolla

The corolla is made up of the petals, but it should be noted that when the sepals and the petals have the same color, they are called tepals. It is in charge of attracting the insects that will pollinate the flower.

Corolla types

According to its symmetry:

• Actinomorphic: is the one that can be divided into identical sections.
• Zygomorphic: is the one that, if cut in half, two different halves would be obtained.

Related article:

What is an actinomorphic and a zygomorphic flower?

According to the union of the petals:

• Dialipet it: in this type the petals are not united.
  • Examples: Rosa (roses), Dianthus (carnation), Papaver (poppies).
• gamopetala: in this case, the petals are fully or partially united.
  • Examples: Campanula, Lamium, Erica (heather), Vaccinium (blueberry).

Chalice

The chalice is the outermost part of the perianth, and is made up of the sepals whose function is to protect the structure of the flower. It is usually green in color, and has a modified leaf appearance.

Sepals they can have a wide variety of shapes and lifespan, depending on the type of plant. For example, in compound flowers, they are reduced to hairs called papus or vilano.

In addition, in the case of many fruit trees, such as Malus domestica (apple tree), these are kept on the plant until the fruit is fully ripe. On the contrary, in Papaver (poppies), they fall as soon as the flower opens.

How many types of perianth are there?

There are three types:

• Monoclamid perianth: when it has no petals or sepals.
• Homoclamid perianth: if it has the same petals and sepals, in which case the flower is said to have tepals.
• Heteroclamide perianth: is when the petals and sepals are different.

And there is also another type of flower, which is the so-called aclamide flower. This is the one without a perianth.

Did you know the characteristics of the perianth?