Lab 10Lycophyta, Psilotophyta

Vascular plants

• General features of the land plants• Common name: Vascular plants• Synonyms: Tracheophyta• Growth habit: Multicellular: stems,

leaves, and roots; thalloid gametophytes• Undulipodia (“flagella”): Whiplash (2

to 1000+)• Conductive cells: Sieve cells, forming

phloem (food), and tracheids, forming xylem (water)

Vascular plants

• Clonal reproduction: Vegetative, various multicellular propagules

• Sexual reproduction: Homosporous or heterosporous

• Included Phyla: Lycophyta, Psilotophyta, Sphenophyta, Pterophyta, Cycadophyta, Ginkgophyta, Coniferophyta, Gnetophyta, Anthophyta

• Recognized by: Free-living, branched Sporophytes; xylem

Tetrads

Lycophyta

• General features of the vascular plants• Common name: Club mosses (applies

also to the Class Lycopodiopsida)• Synonyms: None• Sporophyte growth habit: Stems,

leaves, roots• Gametophyte growth habit:

Photosynthetic or parasitic thalli

Lycophyta

• Stele: Protostele• Undulipodia (“flagella”): Two or more

whiplash• Sexual reproduction: Homosporous

or heterosporous• Representative genera: Isoetes, Lycopodium, Selaginella

• Recognized by: Meiosporangia on upper surfaces of sporophylls

Lycopodium

Lycophyta: Lycopodiopsida

Lycopodium stem

Lycophyta: Lycopodiopsida

Lycopodium strobilus

Lycophyta: Lycopodiopsida

Selaginella

Lycophyta: Selaginellopsida

Selaginella “resurrection plant”

Lycophyta: Selaginellopsida

Selaginella “sporeling”

Lycophyta: Selaginellopsida

Selaginella strobilus

Lycophyta: Selaginellopsida

Selaginella strobilus

Lycophyta: Selaginellopsida

Isoetes

Lycophyta: Isoetopsida

Isoetes megaspores and microspores

Lycophyta: Isoetopsida

Psilotophyta

• General features of the vascular plants• Common name: Whisk ferns• Synonyms: Psilophyta• Sporophyte growth habit: Stems• Gametophyte growth habit: parasitic

branching thalli

Psilotophyta

• Stele: Protostele• Undulipodia (“flagella”): Two or more

whiplash• Sexual reproduction: Homosporous• Representative genera: Psilotum, Tmesipteris

• Recognized by: No leaves or roots; dichotomous branching; synangia

Psilotum

Psilotophyta

Psilotum rhizomes

Psilotophyta

Psilotum rhizome

Psilotophyta

Psilotum meiosporangium

Psilotophyta

Appearances can be deceiving