The key difference between imbricate and twisted aestivation is that imbricate aestivation is a type of aestivation where the margins of appendages overlap with one another but not in any regular direction, while twisted aestivation is a type of aestivation where the margins of appendages overlap with one another in a particular direction.
Aestivation describes the positional arrangement of the parts of a flower (appendages or perianth) within a flower bud. Technically, it is the organization of calyx (sepals) and corolla (petals) relative to each other in a floral bud. Calyx and corolla are collectively called the perianth. Aestivation is sometimes referred to as prefoliation. Therefore, imbricate and twisted aestivation are two types of aestivations in flowers.
CONTENTS
1. Overview and Key Difference
2. What is Imbricate Aestivation
3. What is Twisted Aestivation
4. Similarities – Imbricate and Twisted Aestivation
5. Imbricate vs Twisted Aestivation in Tabular Form
6. Summary
What is Imbricate Aestivation?
Imbricate aestivation is a type of aestivation where the margins of appendages overlap with one another but not in any regular direction. In this type of aestivation, the outermost whorl or the perianth (includes petals and sepals) overlap with each other in a way that few petals are entirely inside, and some are entirely outside. In this type of aestivation, there is an irregular overlapping of petals with each other. Therefore, the overlapping of the calyx (sepals) or corolla (petals) in imbricate aestivation is non-specific. This overlapping does not occur in a specific position.
Figure 01: Imbricate Aestivation
Furthermore, there are two types of imbricate aestivation: ascending imbricate and descending imbricate. In ascending aestivation, the posterior petal is innermost. Examples of this kind of imbricate aestivation can be seen in Cassia, Bauhinia, and gold mohr. In descending imbricate aestivation, on the other hand, the anterior petal is innermost while the posterior petal is outermost. Examples of this kind of imbricate aestivation can be seen in pea plants. Quincuncial aestivation is a modification of imbricate aestivation that can be seen in Murraya and Ranunculus.
What is Twisted Aestivation?
Twisted aestivation is a type of aestivation where the margins of appendages overlap with one another in a particular direction. It is also called contorted or convolute aestivation. In this type of aestivation, the sepals or petals are organized in such a way that one edge overlaps with the next edge inside.
Figure 02: Types of Aestivation
In twisted aestivation, one petal margin overlaps that of the next one, and the other petal margin overlaps that of the next one. Therefore, they regularly overlap with the neighbouring members on one side. Furthermore, the overlapping does occur in a specific position. The popular examples are flowers of Hibiscus, okra, and cotton.
What are the Similarities Between Imbricate and Twisted Aestivation?
- Imbricate and twisted aestivation are two types of aestivations in flowers.
- Both types are based on the positional arrangement of the parts of a flower (appendages or perianth) within a flower bud.
- These types of aestivations can be used to differentiate the flowers of plants.
- Both types of aestivations explain the arrangement of the petals and sepals (perianth) inside a floral bud before blooming.
What is the Difference Between Imbricate and Twisted Aestivation?
Imbricate aestivation is a type of aestivation where the margins of appendages overlap with one another but not in any regular direction, while twisted aestivation is a type of aestivation where the margins of appendages overlap with one another in a particular direction. So, this is the key difference between imbricate and twisted aestivation. Furthermore, another significant difference between imbricate and twisted aestivation is that the overlapping of the calyx (sepals) or corolla (petals) in imbricate aestivation is non-specific, while the overlapping of the calyx (sepals) or corolla (petals) in twisted aestivation is specific.
The following infographic summarizes the difference between imbricate and twisted aestivation in tabular form for side by side comparison.
Summary – Imbricate vs Twisted Aestivation
Aestivation in plants can be explained as the arrangement of the petals and sepals (perianth) inside a floral bud before blooming. It is one of the factors through which one can classify flowers. Imbricate and twisted aestivation are two types of aestivations in flowers. Imbricate aestivation is a type of aestivation where the margins of appendages overlap with one another but not in any regular direction. Twisted aestivation is a type of aestivation where the margins of appendages overlap with one another in a particular direction. Thus, this is the key difference between imbricate and twisted aestivation.
Reference:
1. Gupta, Purva. “Valavte, Twisted ,Imbricate , Quincunical& Vexillary Types of Aestivation.” Blogger, 18 June 2020.
2. “Aestivation and PERIANTH (With Diagram): Flower.” Biology Discussion, 16 Oct. 2015.
Image Courtesy:
1. “Little white flower” By spodzone (CC BY-NC-ND 2.0) via Flickr
2. “Aestivation” By Griensteidl – self-made = self drawn; information taken from Peter Leins: Blüte und Frucht. Morphologie, Entwicklungsgeschichte, Phylogenie, Funktion, Ökologie. E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart 2000. ISBN 3-510-65194 (CC BY-SA 3.0) via Commons Wikimedia