LycopodiophytaLycopodiophyta

Damnjanović Ivana

CharacteristicsCharacteristics Lycopods have Lycopods have greengreen, , branched stemsbranched stems, , small scale-like small scale-like

leavesleaves, and , and rhizomesrhizomes (underground stems which (underground stems which spread and grow new plants).spread and grow new plants).

HabitatHabitat wetlandswetlands

Instead of flowers and seedsInstead of flowers and seeds, Lycopods , Lycopods release release sporesspores from areas on their leaves. from areas on their leaves.

Spores travel to new places and start new Spores travel to new places and start new plants.plants.

Lycophytes have a Lycophytes have a dominant and complex dominant and complex sporophyte generationsporophyte generation..

Lycophytes have a Lycophytes have a gametophyte generationgametophyte generation that that develops independently of the sporophyte,develops independently of the sporophyte, in some cases in in some cases in association withassociation with symbiotic symbiotic fungi.fungi.

Lycopods areLycopods are homosporous homosporous (they produce (they produce only one type of spore), whereas some are only one type of spore), whereas some are heterosporousheterosporous,, producing megaspores and producing megaspores and microspores. microspores.

Gametophytes are bisexual; the sperm-producing Gametophytes are bisexual; the sperm-producing antheridia andantheridia and the egg-producing the egg-producing archegoniaarchegonia occur on the same plantoccur on the same plant. .

FertilizationFertilization takes place after a flagellated sperm takes place after a flagellated sperm swims to the archegonium. swims to the archegonium.

Lycopodium clavatum

In growth habit, the aerial portions of sporophytes In growth habit, the aerial portions of sporophytes of Lycopodium species may of Lycopodium species may rise from a system of rise from a system of rhizomes rhizomes (underground stems).(underground stems).

The The leavesleaves may be spirally arranged or grouped in may be spirally arranged or grouped in four vertical rows along thefour vertical rows along the shootshoot..

Adventitious rootsAdventitious roots

SporophyllsSporophylls may be aggregated into definite may be aggregated into definite strobilistrobili, or there simply may be fertile and sterile , or there simply may be fertile and sterile regions along a stem, the sporophylls resembling regions along a stem, the sporophylls resembling vegetative leaves. vegetative leaves.

Often the sporophylls of compact strobili differ Often the sporophylls of compact strobili differ from the from the vegetative leaves of the same plantvegetative leaves of the same plant..

SelaginellaSelaginella

Selaginella species have Selaginella species have foliage leavesfoliage leaves only only a a few millimetres longfew millimetres long Branching is usually dichotomousBranching is usually dichotomous

                   

LepidodendronLepidodendron   was a giant was a giant tree-like club moss. It towered tree-like club moss. It towered to 45 m in height and flourished to 45 m in height and flourished in the swamp forests.in the swamp forests.  

Fossil formsFossil forms

 Reconstruction of Asteroxylon by Kidston and Lang (1920b, 1921a)showing aerial axes, dichotomous and lateral branches with scale-like 'leaves' or enations and naked cylindrical rhizomes.