Botany

Definition:

Botany, branch of biology that deals with the study of plants, including their structure, properties, and biochemical processes. Also included are plant classification and the study of plant diseases and of interactions with the environment.

Branches of botany:

There are 5 branches of botany

• Plant Pathology.
• Plant ecology
• Palaeobotany. …
• Archaeobotany. …
• Forensic Botany.

Plant Pathology:

Plant pathology is the science that studies the causes of plant diseases, the mechanisms by which diseases develop in individual plants and in plant populations, and the ways and means by which plant diseases can be managed or controlled.

Plant ecology:

Plant ecology is a subdiscipline of ecology that studies the distribution and abundance of plants, the effects of environmental factors upon the abundance of plants, and the interactions among plants and between plants and other organisms.

Palaeobotany:

Paleobotany is the scientific study of ancient plants, using plant fossils found in sedimentary rocks. These fossils can be impressions or compressions of the plants left on the rock’s surface, or “petrified” objects, such as wood, which preserve the original plant material in rocklike form.

Archeobotany:

Archaeobotany is the study of ancient plant remains. By studying archaeobotanical remains we can find out how people used plants in the past: for food, fuel, medicine, symbolic or ritual purposes, or for building and crafts

Forensic botany:

Forensic botany, otherwise known as plant forensics, is the use of plants in criminal investigations. This includes the analysis of plant and fungal parts, such as leaves, flowers, pollen, seeds, wood, fruit, spores and microbiology, plus plant environments and ecology.

History of botany:

Plants are the major source of life on earth. They provide us with food, oxygen and a variety of raw materials for various industrial and domestic purposes. That is why humans have always been interested in plants since time immemorial.

The Greek scholar Theophrastrus  was one of the early Botanists of the world. He is also known as the “Father of Botany” due to his major writings on plants. One of his books called “Enquiry into Plants” classified the plants based on the geographical ranges, sizes, uses and growth patterns. The other work called “On the Causes of Plants” explained the economics of growing plants.

Dioscorides was another Greek physician from 90-40 A.D. who wrote an encyclopedia about herbal medicines known as “De Materia Medica”. This book was used as an important medicinal guidebook for over 1500 years until the invention of the compound microscope.

The invention of the compound microscope by Robert Hooke in 1665 marked the advancement of scientific knowledge in the field of Botany. It helped in the study of the anatomy and physiology of plants. The discovery of chlorophyll helped in understanding the process of photosynthesis. Gregor Mendel studied the genetic inheritance in plants through his experiments on pea plants.

Anatomy:

Robert Hooke’s microscope which he described in the 1665 Micrograhia: he coined the biological use of the term cell .In the first half of the 18th century botany was beginning to move beyond descriptive science into experimental science. Although the  microscope was invented in 1590 it was only in the late 17th century that lens grinding provided the resolution needed to make major discoveries. Antony van leuwenhoek is a notable example of an early lens grinder who achieved remarkable resolution with his single-lens microscopes.

Important general biological observations were made by  (1635–1703) but the foundations of plant anatomy were laid by Italian Marcello Marpigi(1628–1694) of the University of Bologna in his Anatomy Plantarum (1675) and Royal Society Englishman Nehemiah Grew (1628–1711) in his The Anatomy of Plants Begun (1671) and Anatomy of Plants (1682). These botanists explored what is now called developmental anatomy and morphology by carefully observing, describing and drawing the developmental transition from seed to mature plant, recording stem and wood formation. This work included the discovery and naming of  parenchyma and stomata.

Physiology

 Plant physiology

In plant physiology research interest was focused on the movement of sap and the absorption of substances through the roots. Jan Helmont(1577–1644) by experimental observation and calculation, noted that the increase in weight of a growing plant cannot be derived purely from the soil, and concluded it must relate to water uptake. Englishman Stephen Hales (1677–1761) established by quantitative experiment that there is uptake of water by plants and a loss of water by transpiration and that this is influenced by environmental conditions: he distinguished “root pressure”, “leaf suction” and “imbibition” and also noted that the major direction of sap flow in woody tissue is upward. His results were published in Vegetable Staticks (1727) He also noted that “air makes a very considerable part of the substance of vegetables”. 

English chemist Joseph priestly(1733–1804) is noted for his discovery of oxygen (as now called) and its production by plants. Later Jan ingenhousz (1730–1799) observed that only in sunlight do the green parts of plants absorb air and release oxygen, this being more rapid in bright sunlight while, at night, the air (CO₂) is released from all parts. His results were published in Experiments upon vegetables (1779) and with this the foundations for 20th century studies of carbon fixation were laid.

From his observations he sketched the cycle of carbon in nature even though the composition of carbon dioxide was yet to be resolved. Studies in plant nutrition had also progressed. In 1804  (1767–1845) Recherches Chimiques sur la Végétation was an exemplary study of scientific exactitude that demonstrated the similarity of respiration in both plants and animals, that the fixation of carbon dioxide includes water, and that just minute amounts of salts and nutrients (which he analyzed in chemical detail from plant ash have a powerful influence on plant growth.