Although the sporophytes of seedless vascular plants can live on land, their gametophytes cannot because they lack vascular tissues and the male gametes must have water to reach the eggs. Seedless vascular plants typically live in wet, humid places.
Whisk ferns look like whisk brooms and are not true ferns. They are popular ornamental plants common to tropical and subtropical areas.
The sporophytes have no roots or leaves, but rather consist of a system of scalelike branches. The stem houses the xylem and phloem as well as surface cells capable of photosynthesis. Underneath the ground surface short, branching rhizomes serve an absorptive function.
Lycophytes were once tree-sized but now are represented by small club mosses on the forest floor. The sporophyte has true roots, stems, and small leaves containing the vascular tissue. Strobili bear spores that germinate to form small, free-living gametophytes.
The ancient relatives of horsetails were treelike. Only the moderately sized Equisetum has survived. The sporophytes possess underground stems called rhizomes. The scalelike leaves are arranged in whorls around the hollow, photosynthetic stem. Spores are produced inside cone-shaped clusters of leaves at the shoot tip.
Most ferns have a perennial underground stem (called a rhizome). Roots and fronds arise from the rhizome. Young fronds are coiled "fiddleheads". Mature fronds are divided into leaflets. Spores form on the lower surface of some fronds. Sori are clusters of sporangia that release spores that develop into small heart-shaped gametophytes.
This animation (Audio - Important) describes the fern life cycle.
REVIEW: In horsetails, lycophytes, and ferns,
REVIEW: Rhizomes in the whisk ferns serve the same function as __________ in more advanced land plants.
REVIEW: Whisk ferns, lycophytes, horsetails, and ferns are classified as _____ plants.
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