The word ‘plant’ covers    a wide range of living organisms, all of which belong to the kingdom Plantae and share a range of characteristics. The kingdom Plantae is vast. 

Land plants are multicellular organisms that can be distinguished from other living things by the following key characteristics:

• They make their own food – plants are photosynthetic and contain a green pigment called chlorophyll, enabling them to convert energy from the sun into food, subsequently stored as starch.
• Most are rooted in one place – some plants can orientate leaves towards the sun and some respond to touch. 
• Cell walls are rigid – because they are made of cellulose.
• Life cycle includes both a sporophyte and a gametophyte generation. The two generations alternate, each giving rise to the other. This is called ‘alternation of generations’.

Botanists use these and other characteristics to further define plants into groups. For more information you can read our FAQ on vascular or non-vascular plants. 

Plants can be either vascular or non-vascular. 

Vascular plants are called ‘vascular’ because they have a system of ‘tubes’ that connect all parts of the plant (e.g., roots, shoots, leaves) to transport water, nutrients and manufactured food around. These tubes, called xylem and phloem, also form part of the structural support for plants. The four main groups of vascular plants include flowering plants, conifers, ferns, and club mosses.

Non-vascular plants are those without a vascular system (xylem and phloem) and grow from spores. They do not have roots, stems, or leaves, although the lobes of some liverworts can look like leaves. Some non-vascular plants, however, do possess specialised tissues for internal transport of water. Non-vascular plants include two groups – the bryophytes and algae.