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.