The End of Botany

The diverse plant life on Earth—consisting of nearly 400,000 species—can be divided into three broad categories based on biological characteristics: nonvascular, seedless vascular, and seed plants.

The primary organs of vascular plants are roots, stems, and leaves, but these structures can be highly variable, adapted for the specific needs and environment of different plant species.

From Water to Land

Crop cultivation has a long history in human civilization, with records showing the cultivation of cereal plants beginning at around 8000 BC. This early plant breeding was developed primarily to provide a steady supply of food.

Plants have a life cycle split between two multicellular stages: a haploid stage—with cells containing one set of chromosomes—and a diploid stage—with cells containing two sets of chromosomes. The haploid stage is the gamete-producing gametophyte, and the diploid stage is the spore-producing sporophyte.

Plant morphogenesis—the development of a plant’s form and structure—involves several overlapping developmental processes, including growth and cell differentiation. Precursor cells differentiate into specific cell types, which are organized into the tissues and organ systems that make up the functional plant.