Non-vascular Plant - Non-vascular Groups

Non-vascular Groups

The term non-vascular plant is no longer used in scientific nomenclature. Non-vascular plants include two distantly related groups:

• Bryophytes - Bryophyta (mosses), Marchantiophyta (liverworts), and Anthocerotophyta (hornworts). In these groups, the primary plants are the haploid gametophytes, with the only diploid portion being the attached sporophyte, consisting of a stalk and sporangium. Because these plants lack water-conducting tissues, they can't become as tall as most vascular plants.
• Algae - especially the green algae. Recent studies have demonstrated that the algae actually consist of several unrelated groups. It turns out that common features of living in water and photosynthesis were misleading as indicators of close relationship. Only the Archaeplastida are still considered relatives of the plants.

Both of these groups are occasionally termed the "lower plants"; the term "lower" refers to these plants' status as the earliest plants to evolve. However, the term "lower" plants is not precise, since it frequently is used to include some vascular plants, the ferns and fern allies.

In the past, the term non-vascular plant included not only all the algae, but also the fungi as well. Today, it is recognized that these groups are not closely related to plants, and have a very different biology.