System of Plant Classification

How are the land plants classified? This text adopts a five kingdom system. Monera, Protista (which includes the algae), and Fungi have already been considered. Land plants can be studied a number of different ways. The emphasis in this text is on simplicity, focusing on the sub kingdom Embryophytes. Embryophytes are subdivided as follows:

bryophytes-land plants lacking vascular tissue:
	liverworts (Marchantid hornworts (Anthoceros) mosses (Mniurn
tracheophytes-land plants having vascular tissue:
	pteridophytes   ferns (Dryopteris) club mosses (Lycopodium)
	spermatophytes
	gymnosperms (coniferous trees) angiosperms (flowering plants)

Bryophytes lack vascular tissue and, thus, take water in through rhizoids (an undifferentiated tissue) and by absorption from the air. Pteridophytes have vascular tissue, producing xylem and phloem in bundles. Spermatophytes are vascular plants that produce seeds.

Each of the primary subdivisions noted preceding is called a division, or phylum (phyla, plural). Phyla are divided into smaller groups as follows:

	Phylum
		Class
			Order
				Family
					Genus
						Species

In writing the scientific name-that is, the genus name and the species name-proper protocol is to begin the genus name with an uppercase letter, the species name with a lowercase letter, and to italicize (or underline to indicate italics) both names.