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
Vascular Plant Terminology #1
• 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 #2
• Homosporousproduction of one
type of spore from
one kind of
sporangium.
• Heterosporousproduction 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
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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)
2. Selaginellaceae (Selaginella)
3. Isoetaceae (Isoetes)
a. Homosporous
b. Heterosporous
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.
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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.
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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
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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