Seedless Vascular Plants

Chapter 17

• True or False.

– Nonvascular plants include the algae and

bryophytes.

– Vascular plants include lycophytes, ferns,

gymnosperms, and flowering plants.

– Xylem and phloem are the names of musical

instruments from Istanbul.

Vascular Tissue System

• Xylem- plant tissue that

conducts water and

minerals.

– Tracheary elements

• Tracheids

• Vessel elements

• Phloem- plant tissue that

conducts food (mainly

sucrose).

– Sieve elements

• Leaves- photosynthetic, principal lateral appendages of the stem.

– Microphylls- small leaves that contain a single strand of vascular tissue.

– Megaphylls- large leaves that contain multiple strands of vascular tissue.

Vascular Plant Terminology #1

Vascular Plant Terminology #2

• Homosporous-production of one type of spore from one kind of sporangium.

• Heterosporous-production of two types of spores from two different kinds of sporangia.

Vascular Plant Terminology #3

• Sporophyll- a modified leaf that bears sporangia.

– Sporangium- a structure that produces spores.

Vascular Plant Terminology #4

• Microsporophyll- a modified leaf that bears microsporangia.

– Microsporangia- a sporangium that produces microspores.

• Megasporophyll- a modified leaf that bears megasporangia.

– Megasporangia- a sporangium that produces megaspores.

Vascular Plant Terminology #5

• Strobilus- a reproductive structure consisting of

nonphotosynthetic sporophylls; a cone.

– Microstrobilus- a microsporangiate cone.

– Megastrobilus- a megasporangiate cone.

Extinct Seedless Vascular Plants

• Representatives (425-370 MYA)

– Rhyniophyta

– Zosterophyllophyta

– Trimerophytophyta

Extant Seedless Vascular Plants

• Phyla (Living today)

– Lycopodiophyta- club mosses, resurrection plant, quillworts.

– Monilophyta- ferns and the fern allies (whisk ferns and horsetails).

Lycopodiophyta- lycophytes

• Lykos- gr. wolf, pous- gr. foot.

• Microphylls present.

• Plants + or - dichotomously branched.

• Sporangia on or in the axils of sporophylls on strobili.

• Heterosporous & homosporous.

• Distribution- global.

• Habitat- forest floors, deserts, aquatic.

• ~1,200 species.

• Examples- Lycopodium, Selaginella, Isoetes).

Lycopodium

Selaginella- the resurrection plant

(Selaginellaceae) is heterosporous.

Isoetes- the quillwort (Isoetaceae)

is heterosporous.

• Match spore type on the right to lycophyte

family on the left.

1. Lycopodiaceae (Lycopodium) a. Homosporous

2. Selaginellaceae (Selaginella) b. Heterosporous

3. Isoetaceae (Isoetes)

Monilophyta- ferns and fern allies.

• Monilo- gr. single string of beads.

• Leaves- megaphylls, scalelike, & microphyll-like.

• Variable branching patterns.

• Sporangia in sori, lateral, or on sporangiophores in strobili.

• Heterosporous & homosporous.

• Distribution- global, tropics.

• Habitat- all habitats, > species in moist.

• ~11,000 species.

• Examples- Polypodium, Psilotum, Equisetum).

Class Psilotopsida

Order Psilotales- whisk ferns.

• Psilos- gr. bare.

• Leaves- scale-like or megaphyll-like.

• Eusporangiate.

• Sporangia lateral.

• Dichotomous and pinnately branched.

• Homosporous.

• No roots, but they have aerial stems.

• Distribution- tropical & subtropical.

– Alabama, Arizona, Florida, Louisiana.

• Habitat- epiphytic or on rich soils.

• Examples- Psilotum (2 spp.) and Tmesipteris (13 spp.).

Tmesipteris

Class Psilotopsida

Order Ophioglossales- ferns.

• Ophio- gr. serpent. Gloss- gr. tongue.

• Leaves- megaphylls.

• Eusporangia in 2 rows.

• Sporangia on outer edge or sunken.

• Dissected or unbranched.

• Homosporous.

• Roots, stems, and leaves.

• Distribution- tropical and temperate.

• Habitat- epiphytic or soil.

• ~80 species

• Examples- Botrychium and Ophioglossum.

Class Marattiopsida

• Mara- gr. marlstone- lime-rich soil.

• Leaves- megaphylls, complex, pinnately branched.

• Sporangia eusporangiate, homosporous.

• Sporangia on lower surface of leaves.

• Distribution- tropical and subtropical.

• Habitat- epiphytic and soil.

• ~200 species.

• Example- Marattia.

Class Polypodiosida- ferns

• Poly- L. many. podio- gr. footed.

• Leaves- megaphylls, fronds.

• Sporangia leptosporangiate, homosporous and heterosporous.

• Sporangia usually in sori.

• Compound branching, but not dichotomous.

• Roots, stems, and leaves.

• Distribution- global, tropical.

• Habitat- all habitats, > species in soil.

• ~10,500 species.

• Example- Polypodium.

Polypodium

Class Equisetopsida- horsetails

• Equus- L. horse, saeta- L. bristle.

• Leaves- microphyll-like, scaly.

• Homosporous.

• Sporangia eusporangiate, on sporangiophores in a strobilus.

• Whorled leaves, but not dichotomous.

• Roots and stems (ribbed and jointed).

• Distribution- global.

• Habitat- along streams in moist sites.

• ~15 species.

• Example- Equisetum.

Equisetum