Download - Seedless Plants Ch12.2 7th PDF
Seedless PlantsChapter 12 Section 2
Objectives:
• List 3 nonvascular plants and 3 seedless plants
• Explain how seedless plants are important to the environment
• Describe the relationship between seedless vascular plants and coal
Is that a fact!!
• Photographers (in the old days) created an explosive flash of light with powder.
• The powder contained spores from club mosses (seedless vascular plants)
2 Groups of Plants That Do Not Make
Seeds:
• Nonvascular plants: mosses, liverworts, and hornworts
• Vascular plants: ferns, horsetails, and club mosses
1. Nonvascular Plants:
• Are small
• Grow on soil, bark of trees, and rocks
• Live in places that are damp
• Do not have true stems, roots, or leaves
Mosses -
• Live together in large groups
• Cover soil or rocks with a “mat”
• Have leafy stalks and rhizoids (root-like structure that holds these plants in place)
• Rhizoids help the plants get water & nutrients
• 2 stages to their life cycle (sporophyte/gametophyte)
Mosses -
http://www.science-art.com/gallery/47/47_6292006204817.jpg
Liverworts & Hornworts -
• Also are small
• Live in damp places
• Similar life cycle:▫ Gametophytes of liverworts can be leafy & moss-
like or broad & flattened▫ Gametophytes of hornworts are broad and
flattened▫ Both have rhizoids
Liverworts & Hornworts -
http://www.biology-blog.com/images/blogs/10-2006/plants-cycle-561.jpg
The Importance of Nonvascular Plants
• Usually the 1st plants to live in a new environment (ex: newly exposed rock)
• They form a thin layer of soil after they die (reduces soil erosion)
• Animals eat or nest in them (habitat, food)
• Peat mosses: useful to humans (fuel, potting soil)
2. Seedless Vascular Plants:
• Larger than nonvascular plants
• Include ferns, horsetails, and club mosses
• Have specialized vascular tissue
Ferns -
• Grow in a variety of places (cold to warm)
• Small or large
• Rhizome: an underground stem from which new leaves and roots grow
• Leaves: fronds coil (fiddleheads)
Ferns -
• Sporophyte: leafy fern
• Gametophyte: tiny; about the size of your fingernail (green and flat – shaped like a heart)
http://botit.botany.wisc.edu/images/130/Ferns/Sporophyte_images/Fern_labeled_MC_.jpg
Ferns – life cycle
http://media-2.web.britannica.com/eb-media/59/72159-035-14F9199A.jpg
Horsetails & Club Mosses -
• Horsetails:
▫ Grow in wet marshy places
▫ Stems are hollow and contain silica (gritty texture) – scouring rushes
▫ Similar life cycles to ferns
• Club Mosses:
▫ Grow in woodlands
▫ Not actually mosses – have vascular tissue
▫ Life cycle similar to ferns
Horsetails -
http://www.sdnhm.org/valentien/plantportraits/samples/03-35_horsetail250x400_ol.jpg
Club Mosses -
http://www.uwsp.edu/biology/courses/botlab/images/Lab22Ferns/22IB1a.JPG
Importance of Seedless Vascular
Plants: • Help form soil
• Help prevent soil erosion
• Formation of communities
• Popular house plants
• Some are edible
• Shampoos, dietary supplements, skin-care products…
• Remains of ancient seedless vascular plants formed coal
Quick Quiz:
• What is the difference between a rhizoid and a rhizome?
• Describe the environmental importance of mosses, liverworts, and hornworts.