19 Seedless Vascular Plants

These flashcards cover key concepts related to seedless vascular plants, specifically lycophytes, their morphology, reproductive strategies, and ecological adaptations.

What phylum is known as the first extant phyla of seedless vascular plants?

Phylum Lycopodiophyta.

How many living genera and species does the Phylum Lycopodiophyta comprise?

10-15 living genera comprising approximately 1200 species.

What significant split occurred approximately 400 million years ago in lycopods?

The lycophyte clade split from the euphyllophyte clade.

What type of plant morphology is characteristic of living lycophytes?

All living lycophytes are small and herbaceous.

What is a notable feature of club mosses?

Protostelic with microphylls spirally arranged.

What is the evolutionary origin difference between microphylls and megaphylls?

Microphylls evolved from outgrowths called enations, while megaphylls resulted from the fusion of branch systems.

What type of sporangia occurs on sporophylls in homosporous lycophytes?

Sporangia occur on specialized microphylls.

What are the two types of gametophytes that arise from spore germination?

Bisexual gametophytes that can be green or subterranean.

What is unique about the reproductive structures of the Selaginellaceae family?

They are heterosporous with unisexual male and female gametophytes.

What process allows some Isoetes species to acquire carbon for photosynthesis at high altitudes?

They use sediment rather than the atmosphere for carbon acquisition.

What distinguishes Isoetes from other seedless vascular plants?

Isoetes appears with quill-like microphylls and has a specialized cambium in the corm.

Which family contains the resurrection plant, and how many species does it have?

Family Selaginellaceae, with approximately 750 species.

How long can the development of archegonia and antheridia take in lycophyte gametophytes?

6-15 years.

What is a unique reproductive trait observed in male gametophytes of the Selaginellaceae family?

Male reproductive structures lack chlorophyll and consist of one non-photosynthetic cell.

What major advantage does CAM photosynthesis provide to Isoetes species?

It allows them to photosynthesize without stomata, especially during periods of dehydration.