seedless vascular plants

Pharmaceutical Botany with Taxonomy
Seedless Vascular Plants
Llamera, John David M.
Llarenas, Marie Ethene Van V.
Meredores, Ken Charles M.
Montes, Rene

,Important Concepts
The Interpolation Theory
 Postulates that a small
sporophyte came into existence
when a zygote germinated
mitotically instead of meiotically.

The Transformation Theory
 Postulates that after dibiontic
cycle originated, both gametophyte
and sporophyte became larger, more
complex, and vascularized, in a life
cycle with an alternation of
isomorphic generation.

,Early Vascular Plants: Rhyniophytes

 The rhyniophytes are a group of
extinct spore-bearing vascular
plants that were leafless and
rootless, with upright branching
stems.

, Early Vascular Plants: Rhyniophytes
 Cooksonia – a genus of extinct plants.  Rhynia & Aglaophyton
− Upright stem & equal dichotomous − Had prostrate rhizome
branches − Upright naked stems
− Had epidermis with a cuticle, a cortex − Terminal sporangia
of parenchyma, and a xylem − Stomata and guard cel
composed of tracheids epidermis, and a cuticle la
− Had large, multicellular masses of − Homosporous
sporogenous tissue
− Homosporous