Vascular plant

All plants may be roughly divided into two general groups, vascular and nonvascular plants. Vascular plants include those that we consider to be "higher" plants, specifically including:

• lycopods[?] (clubmosses, spikemosses, quillworts)
• Lycophyta
• horsetails
• whiskbrooms[?]
• ophioglossoids (adders-tongues, grape-ferns[?]
• ferns
• flowering plants

These plants are differentiated from the "lower" plants such as the mosses, liverworts[?], hornworts[?] and green algae in two particularly important ways. In non-vascular plants, the principal generation is the gametophyte generation, which is haploid, or has one set of chromosomes per cell. In vascular plants, the principal generation is the sporophyte[?] generation, which is diploid, or has two sets of chromosomes per cell. See also alternation of generations.

The other critical difference is that vascular plants have water-carrying structures, termed tracheids[?], in their tissues, enabling the plants to evolve larger and more elaborate structures, while non-vascular plants lack these.