Themosses,phylum Bryophyta, are most often recognized as the green “fuzz” on damp
rocks and trees in a forest. If you look closely, you will see that most mosses have tiny stem-
like and leaf-like structures. This is the gametophyte stage. Remember from lesson 1 that
the gametophyte is haploid. The gametophyte produces the gametes that, after fertilization,
develop into the diploid sporophyte. The sporophyte forms a distinctive capsule, called the
sporangium, which releases spores (Figure10.8).
Figure 10.8: Sporophytes sprout up on stalks from this bed of moss gametophytes. Notice
that both the sporophytes and gametophytes exist at the same time. ( 31 )
Thehornworts, phylum Anthocerophyta, get their name from their distinctive hornlike
sporophytes, and “wort” which comes from the Anglo-Saxon word for herb. The hornlike
sporophytes grow from a base of flattened lobes, which are the gametophytes (Figure10.9).
They tend to grow in moist and humid areas.
Liverworts,phylum Hepatophyta, have two distinct appearances- they can either be leafy
like mosses or flattened and ribbon-like. Liverworts get their name from the type with the
flattened bodies which can resemble a liver (Figure10.10). Liverworts can often be found
along stream beds.
Vascular Seedless Plants
As their name implies, vascular seedless plants have vascular tissue but do not have seeds.
Vasculartissueisspecializedtissueswhichconductwaterandnutrientsthroughouttheplant.
Vascular tissue allowed these plants to grow much taller than nonvascular plants, forming
the ancient swamp forests mentioned previously. Most of these large vascular seedless plants