What is the Difference Between Carpel and Pistil

The main difference between carpel and pistil is that carpel is the female part of the flower, comprising of stigma, style, and ovary, whereas pistil can be either the same as an individual carpel or a collection of carpels fused together. Furthermore, a single pistil can have lots of carpels.

Carpel and pistil are two terms that describe female parts of a flower.  It is possible to use these terms interchangeably when a flower contains a single pistil and a single carpel.

Key Areas Covered

1. What is Carpel
     – Definition, Components, Function
2. What is Pistil
     – Definition, Components, Function
3. What are the Similarities Between Carpel and Pistil
     – Outline of Common Features
4. What is the Difference Between Carpel and Pistil
     – Comparison of Key Differences

Key Terms

Carpel, Female Part of the Flower, Ovary, Pistil, Stigma, Style

What is Carpel

A carpel is a set of female reproductive structures in a flower. It contains an ovary, stigma, and style. Moreover, it is a megasporophyll, which is a modified leaf bearing ovule. Generally, the expanded basal portion of the carpel is the ovary, containing placentas. Placentas are ridges of tissues bearing one or more ovules. Furthermore, the three parts of the ovule are the integument, the outer layer, the nucellus, the remnant of the megasporangium, and the female gametophyte formed from a haploid megaspore.

Figure 1: Carpel

Moreover, the pillar-like stalk through which the pollen tubes grow to the ovary is the style. Generally, style is responsible for holding the stigma out of the flower to capture pollen grains as well. Meanwhile, stigma is the sticky or feathery portion found on the style responsible for capturing pollen grains.

What is Pistil

The pistil is the female reproductive part of the flower. It may contain a variable number of carpels. Pistils with a single carpel are known as monocarpellary pistils while pistils with many carpels are referred to polycarpellary pistils. Generally, the flowers with a single carpel and single pistil are represented as G(1) by the floral formula. However, when a flower contains three free and distinct carpels with separate ovaries, these three can be counted as three pistils. And, tis conditions can be represented as G(3).

Figure 2: Pistil
a. 3 Simple Pistils, b. 1 Compound Pistil, c. 1 Pistil

Moreover, when a flower contains three carpels with a fused ovary, the pistil is considered as a compound pistil. And, this condition is represented as G(3) by the floral formula. Therefore, in general, the number of ovaries in the flower helps to distinguish the number of pistils while the number of styles helps to distinguish the number of carpels.

Similarities Between Carpel and Pistil

• Carpel and pistil are two terms that describe the female parts of a flower.
• Both are made up of stigma, style, and ovary.
• Moreover, their main function is to produce egg cells, to undergo fertilization, to produce seeds, and to help in the dispersal of seeds.

Difference Between Carpel and Pistil

Definition

Carpel refers to the female reproductive organ of a flower, consisting of an ovary, a stigma, and usually a style, occurring singly or as one of a group, while pistil refers to the ovule-bearing or seed-bearing female organs of a flower. Thus, this explains the main difference between carpel and pistil.

Components

Also, another difference between carpel and pistil is that carpel is made up of an ovary, stigma, and a style while a pistil may contain one or several carpels.

Significance

You can count the number of carpels by counting the number of separate styles and the number of pistils by counting the number of separate ovaries in the flower.  

Function

Furthermore, carpels are responsible for producing egg’s cells, undergoing fertilization, producing seeds, and dispersing the seeds while pistil serves as the female part of the flower. Hence, functionally, this is the difference between carpel and pistil.

Conclusion

The carpel is a set of ovary, stigma, and style. It is responsible for the production of egg cells, undergoing fertilization, production of seeds, and the aiding in the dispersal of seeds. On the other hand, the pistil is the female part of the flower. It may also contain single or several carpels. Moreover, a single flower may contain one or more pistils. In general, the number of ovaries in the flower helps to distinguish the number of pistils while the number of styles helps to distinguish the number of carpels. Therefore, the main difference between carpel and pistil is their representative structures.

References:

1. “Carpel Pistil.” Virtual Herbarium, Charles Sturt University, 19 Sept. 2012, Available Here.
2. “Pistil.” Encyclopædia Britannica, Encyclopædia Britannica, Inc., 16 Feb. 2018, Available Here.

Image Courtesy:

1. “Figure 26 03 02” By CNX OpenStax (CC BY 4.0) via Commons Wikimedia   
2. “Image from page 155 of “The principles of botany, as exemplified in the phanerogamia” (1854)” By Internet Archive Book Images via Flickr