age |
carboniferous
|
division-name |
Lycophyta
|
evolution |
evolved from zosterophyllophytes
|
gametophyte |
.
|
habit |
.
|
leaves |
microphyll.
- lycopodium: photosynthetic, has a single strand
- selaginella: microphylls contain a ligule on upper surface
|
life-cycle |
Homosporous and Heterosporous
- lycopodium: Homosporous
- selaginella: Heterosporous. Produces mega- and microspores. Most of the GTs of heterosporous plants grow in the wall of the spore so it means that the GT is reduced in size and can remain protected by spore. The larger megaspore allows for a development phase of megagametophyte and nourishment for sporophyte.
|
links |
Selaginella Life-cycle Lycopodium Life-cycle More Life-cycles Handy quick reference
|
members |
represented by 3 orders: lycopodiaceae, sellaginellaceae, isoetaceae
|
rhizome |
- lycopodium: gives rise to aerial branches and roots
- selaginella: roots arise adventitiously. Formed from pericycle tissue in the stem
|
roots |
yes. Root and Shoot system.
- lycopodium: roots arise adventitiously
|
sporangia |
Produced on upper surface of sporophylls which are interspersed with microphylls or clumped into a strobilis/cone at the end of a branch.
- lycopodium: The sporangia are found on top of sporphyll and protected into a strobilis. Spores form bisexual gametophyte that is photosyntetic or subterranean & mycorrizal
- selaginella: produced on sporophylls that are always arranged as a strobillis. Microspores produce microgametophyte that produce 1 antheridium. Megaspores produce megagametophyte that produces archegonia. The megagametophyte nourishes embryo and sporophyte
|
stems |
- lycopodium: small plants, with simple/branched stems and microphylls.
- selaginella: branches more freely
|
stomata |
.
|
traits |
.
|
vascular-system |
protostele
- lycopodium: protostele is surrounded by a pericycle. Has meristematic parenchymal cells, and gives rise to root. Leaf traces can be found in the vicinity of the pericycle.
- selaginella: vascular cylinder is supported within airspace by trabeculae
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