Reproduction of Seedless Plants
Seedless plants can reproduce asexually or sexually. Some seedless plants, like hornworts
and liverworts, can reproduce asexually through fragmentation. When a small fragment of
the plant is broken off, it can form a new plant.
Like all plants, nonvascular plants have an alternation of generations lifecycle. In the life-
cycle of the nonvascular seedless plants, the gametophyte is dominant. The gametophyte
is photosynthetic and normally described as the plant. The male gametophyte produces
flagellated sperm that must swim to the egg formed by the female gametophyte. For this
reason, sexual reproduction must happen in the presence of water; hence the nonvascular
plants tend to live in moist environments. Following fertilization, the sporophyte forms.
The sporophyte is connected to and dependent on the gametophyte. The purpose of the
sporophyte is to produce spores that will develop into gametophytes and start the cycle over
again.
For the seedless vascular plants, the sporophyte tends to be dominant. For example, in ferns
thegametophyteisatinyheart-shapedstructure, andtheleafyplantwerecognizeasafernis
the sporophyte (as shown inFigure10.5). The sporangia of ferns are often on the underside
of the fronds (Figure10.16). Like the nonvascular plants, ferns also have flagellated sperm
that must swim to the egg. But unlike the nonvascular plants, once fertilization takes place,
the gametophyte will die and the sporophyte will thrive independently.
Figure 10.16: This fern is producing spores underneath its fronds. ( 17 )