20 Seedless Vascular Plants

These flashcards cover essential topics related to seedless vascular plants, focusing on their classification, diversity, spore types, anatomical features, and evolutionary significance.

What phylum do ferns and horsetails belong to?

Phylum Monilophyta

How many living species of ferns are there approximately?

12,000 living species

Where is fern diversity the greatest?

In the tropics, with ¾ of species found there.

What are the two types of spores that ferns are classified into?

Eusporangiate and Leptosporangiate.

What does a eusporangium produce?

It produces larger quantities of spores and has a more complex structure than a leptosporangium.

What is a characteristic feature of leptosporangium development?

It develops from a single superficial initial and produces a sporangium with a wall one cell thick.

What happens to the lip cells during spore dispersal in leptosporangium?

They dry and contract, creating tension that eventually causes them to rupture.

What are the two orders of Class Psilotopsida?

Ophioglossales and Psilotales.

What is unique about the gametophytes of Botrychium, Ophioglossum, and Psilotum?

They are subterranean, tuberous, and associated with symbiotic fungi.

What are Marattiopsida known for?

Being an ancient group of ferns extending back to the Carboniferous with several living genera.

What is the approximate number of families and species in Class Polypodiopsida?

Approximately 35 families and over 10,500 species.

What is circinate vernation?

The coiled development of young leaves known as 'fiddleheads'.

What is the main feature of the water ferns of the Polypodiopsida?

They are heterosporous, which is unlike the rest of the ferns in this group.

What is the significance of the genus Equisetum?

It is possibly the oldest surviving genus of plants on Earth and known as horsetails.

What function do carinal canals serve in Equisetum?

They are associated with a strand of xylem and phloem, used to transport water during internode elongation.