18 Seedless Vascular Plants

Flashcards based on the lecture notes about seedless vascular plants, covering their evolution, significance, and characteristics.

What is the significance of vascular plants in evolution?

They are part of a monophyletic lineage and have multicellular embryos, separating from green algae.

What distinguishes the gametophyte and sporophyte generations in vascular plants?

In vascular plants, the sporophyte generation is free-living and not dependent on the parental gametophyte.

What evolutionary advancements did vascular plants achieve?

The development of xylem and phloem, as well as the ability to produce lignin, allowing them to grow larger.

What were the three most prominent groups of seedless vascular plants during the Devonian period?

Rhyniophyta, Zosterophyllophyta, and Trimerophytophyla.

When did seedless vascular plants flourish?

During the Devonian period, approximately 360 million years ago.

What are lycopodiophyta and monilophyta?

They are the groups of seedless vascular plants that still have living representatives today.

What characterized the vascular plants during the Middle Silurian to the Middle Devonian?

They were small with simple morphology included rhyniophytes, zosterophyllophytes, and trimerophytes.

What major plant groups emerged after the late Devonian?

Seed plants, including gymnosperms which were dominant most of the Mesozoic era.

What is unique about the phylum Rhyniophyta?

It is the earliest known vascular plant with dichotomously branched stems and sporangia.

How did Rhynia gwynne-vaughanii adapt to its environment?

It likely grew in marshy areas, had a dichotomously branched system, and was covered with a cuticle.

What made Aglaophyton major different from Rhynia gwynne-vaughanii?

It was more robust, around 50 cm tall, and lacked wall thickening in tracheids, making it a protracheophyte.

How is Cooksonia significant in the study of vascular plants?

It is the oldest known vascular plant, characterized by its small size and simple structure.

What is a distinct feature of Zosterophyllophyta?

They lack leaves and have dichotomously branched stems with stomata only on upper stems.

What evolutionary position does Trimerophytophyla occupy?

It likely descends from rhyniophytes and is considered an ancestor of both ferns and progymnosperms.