PLANT ORGANOGRAPHY: HISTORY, WHAT IT STUDIES AND BRANCHES - BIOLOGY - 2025

The plant organography is a science that studies the different tissues and organs of plants. It is a branch of biology, which also supports and complements the studies of other sciences.

However, this discipline is perhaps the least known of all. This may be due to the fact that its study is usually approached by anatomy or histology, which also investigate the organs of the plant.

By Ibib flors, from Wikimedia Commons

The information provided by plant organography is of the utmost importance. It could offer, among other aspects, a general vision of the evolution that has occurred in a certain structure of the plant. This could explain various problems related to germination or flowering.

It also helps to understand the reproductive and vegetative factors of plants, being a decisive factor in the taxonomic classification of plant species.

Currently, molecular organography aims to achieve the integration of the genetic discoveries of recent years with the data offered by morphological and evolutionary botany of previous decades.

History

Aristotle, the eminent philosopher, logician and scientist of ancient Greece, can be considered as the first student of Biology who gave the scientific vision to organography. He considered the different parts of the plant as "organs" and established the relationships between these and the functions they perform.

During the 17th century, Joachim Jung, one of the most scientifically relevant figures of that century, made it clear that plants are made up of structures called organs. He highlighted the existence of the root, the stem and the leaf, defining in each of them its shape, function and position.

Advances in organography continued in the 18th century, when Caspar Friedrich Wolff, considered the father of embryology, investigated metamorphosis in plants in detail.

His studies allowed him to conclude that the rudiments of the leaves have similarities to the parts of the flower and that both derive from a tissue that has differentiated. He also stated that all the parts of a plant, except the stem, are leaves that have undergone modifications.

Theory of metamorphosis

In 1790, the German playwright and scientist Johann Wolfgang von Goethe published a book entitled The Metamorphosis of Plants. In his theory he maintains that all the organs of flowers are the product of the variations that an original shape has undergone.

Goethe exposes the idea that the organs of the plant have originated from modifications of the leaves. Cotyledons are considered to be imperfect leaves. The leaves also give rise, after metamorphosis, to sepals, petals, stamens and pistils.

These ideas about the morphology of plants were the basis of later research work, including that of Charles Darwin.

Related sciences

Plant physiology

This is responsible for studying the metabolic processes that occur in plants. Among them are respiration, germination, photosynthesis, and flowering.

Plant morphology

This includes cytology and histology, because they are responsible for knowing the structure and microscopic shape of the plant.

Plant embryology

It is responsible for studying the structure that houses the spores (sporangia), gametophytes and embryos of the plant.

Palynology

This science, which is a branch of botany, focuses on the study of pollen and spores, which are part of the reproductive structures of plant species.

What do you study? (object of study)

Plant organography is a subdivision of Biology that contemplates the study of the different tissues, systems and organs that make up plants. This leads to the evaluation of the internal cellular structures, as well as examining in detail macroscopic aspects of the plants.

Some of the microscopic aspects of plants that can be object of study by organography are the cell membrane and some organelles such as mitochondria, ribosomes and chloroplasts. They can also study tissues such as the meristem, parenchyma, xylem, and phloem.

At the macroscopic level, the aspects could be the weight, size, shape, color, texture of each of the parts of the plant: root, stem, leaf, flower, fruit and of the seed as its reproductive gamete.

Plant organography takes the information obtained from these aspects and relates it to the function they fulfill in the plant. This allows relationships and differentiations to be established between each species, in order to find similarities and characteristics that allow each group to be defined.

Vegetative life organs

This group of organs are responsible for maintaining the life of the plant. In general, they have the function of transporting substances and nutrition. Among these organs are:

• Root. This organ fulfills the function of fixing and absorbing nutrients.
• Stem. It is the support of the leaves, flowers and fruits of the plant. They are also the transport route for water and nutrients that were absorbed by the root.
• Leaf. Photosynthesis takes place in this organ, in which process oxygen and glucose are produced.

Reproductive organs

Here are grouped the structures responsible for reproducing the plant. These are:

• Seed. These contain the embryo, which as it develops will cause the plant to propagate.
• Flower. It is a reproductive organ composed of modified leaves where the calyx, corolla, androecium and gynoecium are found. They can be of various colors and shapes.
• Fruit. It is an organ of the plant that is formed as a product of the development of the fertilized ovary. Inside it contains the seeds.

Methodology

Plants have a grouping of tissues and organs that form a functional and anatomical unit that allows them to carry out their vital functions. The study of each of the organs and subsystems could be carried out in different ways.

Observations can be carried out, without considering any criteria of causality, using a comparative examination. This methodology is followed in descriptive and comparative morphology. These start from the idea that the variety in the forms are variations of a single type of primitive structure.

Depending on the objective of the investigation and the character that you want to know, you may need to investigate the relationship between the organic form and the cause that originates it.

To achieve this, experiments could be carried out, involving high-tech equipment or instruments, as well as some computerized procedures.

3D imaging

Initially, to calculate the growth rate of a leaf, several dots were drawn with ink on the surface of this organ. The intention was to outline a grid of small rectangles that could be used, over time, to obtain the data that is needed.

Currently there are tools that analyze a sequence of digital images in three dimensions, which allow to automatically track the displacement of the identified feature.

These technological tools include different algorithms and programs that allow the results to be averaged, showing them in the form of spatial maps. This technique is applicable in any other organ of the plant.

Real studies in organography

Reproductive organography of Bougainvillea spectabilis Willd

In 2015, a group of researchers carried out a study on the floral development of Bougainvillea spectabilis Willd, known as bungavilla or trinitaria. This plant is of great importance for horticulture, as well as in the pharmaceutical and environmental industries.

The study was based on the structure and the floral organography in this species. The results showed several specific characteristics in the reproductive organography, such as that only a basal ovule develops within the superior ovary of the flower.

All the information could be very useful to understand the different reproductive factors, including their sterility.

The genus Eugenia (Myrtaceae) in southern Africa: taxometry of foliar organography (1982)

In this research, 6 species belonging to the genus Eugenia L., whose common name is cayenne cherry or currant, were compared. The numerical analyzes of 20 quantifiable properties of the foliar organography were carried out, in order to determine their taxonomic value.

The results were adjusted to the current delimitation of the species, demonstrating the taxonomic value of the foliar organography.

Organographic distribution of vascular elements in the genus Hibiscus L. (1997)

A study was conducted on members of the genus Hibiscus L, known as Chinese rose or cayenne. In this, the organographic distribution and the characteristics of the vascular elements were investigated. The intention was to establish relationships between the different members of this genus.

The investigations revealed, among other things, that the species studied had short vessels. They also have, at their transverse end, with simple perforation plates. These parameters are of great importance in the taxonomic classification of species.

Morphology and quantitative monitoring of gene expression patterns during flower induction and early flower development in Dendrocalamus latiflorus (2014)

Dendrocalamus latiflorus is a genus of bamboo of great ecological importance in tropical and subtropical areas. Its characteristics regarding the morphological constitution and genetic profiles of this plant were evaluated. The purpose is to know the induction and flower development.

The studies of the morphology of the buds and the organography of the flowers were complemented with specialized techniques. Some of these was the use of a scanning electron microscope.

Combined tests provide easy markers, allowing you to trace the transition between the vegetative and reproductive phases.

References

1. Pupuma, RB Bhat (1997). Organographic distribution of vascular elements in the genus Hibiscus L. Sience direct. Recovered from sciencedirect.com.
2. Suxia Xuab, Qingyun Huanga, Qingyan Shuc, Chun Chena, Brady A. Vick (2008). Reproductive organography of Bougainvillea spectabilis Willd. Science direct. Recovered from com.
3. Wikipedia (2018). Organophy. Recovered from en.wikipedia.org.
4. Emmerentiadu Plessis, AEvan Wyk (1982). The genus Eugenia (Myrtaceae) in southern Africa: Taxometrics of foliar organography. Science direct. Recovered from sciencedirect.com.
5. Lauren Remmler, Anne-Gaëlle, Rolland-Lagan (2012). Computational Method for Quantifying Growth Patterns at the Adaxial Leaf Surface in Three Dimensions. NCBI. Recovered from ncbi.nlm.nih.gov.
6. Wang X, Zhang X, Zhao L, Guo Z (2014). Morphology and quantitative monitoring of gene expression patterns during floral induction and early flower development in Dendrocalamus latiflorus. NCBI. Recovered from ncbi.nlm.nih.gov.