Phylum Lycophyta The Ground Pines Spike Mosses And Quillworts

When I was in high school, my father was interviewed by a newspaper reporter in a hotel room of a large South American city. At the end of the interview, which took place

Life Cycle Psilotum

— rhizoid gametophyte archegonium egg

Figure 21.2 Life cycle of Psilotum.

— rhizoid gametophyte archegonium egg

Figure 21.2 Life cycle of Psilotum.

with the rest of the family present, the reporter set up a press camera and said he wanted to take a picture of the family. After posing us, he took a vial from his pocket and poured a little powder along a metal bar attached to one end of a T-shaped device that otherwise looked like a flashlight. He then told us to smile, and a moment later, there was a flash of light followed by a large billow of smoke. I learned later that the flash powder (forerunner of flashbulbs and strobe lights) he had used contained millions of spores of primitive vascular plants collectively called club mosses.

The 950 or so known species of club mosses (referred to in this text as ground pines and spike mosses) mostly look enough like large true mosses that the Swedish naturalist Linnaeus lumped both together in a single class. Once details of the structure and the form of club mosses were known, however, it became obvious that they are quite unrelated to true mosses.

Today, there are living representatives of two major genera and two minor genera of club mosses. Several others became extinct about 270 million years ago. The sporo-phytes of all species have microphylls (leaves with a single unbranched vein that is not associated with a leaf gap—see Chapter 6) that are usually quite small; they also have true stems and true roots.

The two major genera of club mosses with living members are Lycopodium, with about 50 species, and Selaginella, with over 700 species. They are distributed throughout the world, but they are more abundant in the tropics and wetter temperate areas.

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  • Bellino
    What is the ground pines phylum?
    8 years ago

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