Download presentation
Presentation is loading. Please wait.
Published byPauline Dean Modified over 9 years ago
1
Are these two plants the same species? List your reasons for why you think they are or are not.
2
One is a noxious weed, the other is an increasingly rare native The native – Caltha palustris, Marsh Marigold. 5-9 deep yellow petals. Leaves round to kidney shaped.
3
The Alien – Ranunculus ficaria, 8 yellow petals, leaves heart shaped.
4
How would you define a weed?
5
A valueless or unwanted plant that is growing wild, usually crowding out or out competing desired plants or crops How big a problem do you think weeds are in the country?
6
In 1984, the United States lost $7.4 billion in average annual crop yield because of noxious weeds. Noxious weeds are estimated to inhabit over 100 million acres in the United States, and could be increasing by as much as 8-20% every year (US Department of the Interior 1997).
7
Can you name any examples of weeds that could have a negative impact on human health? Hint Simon suffers from this.
8
Greater Ragweed, Artemisia trifida Common ragweed, Artemisia artemisiifolia Plants with lobed and dissected leaves, with spikes of green flowers often carrying yellow pollen Ragweeds
9
Describe this plant
10
Poison Ivy, Rhus radicans Fruit It can be pretty to look at, but often spreads to places where humans work (gardens, garden walls, forest trails, road sides).
11
How would you decide whether or not a plant you come across in the garden is a weed? Group work List some criteria you think fit our definition of a weed
12
1.Its not a plant you put in the garden. The best way to recognize a weed is to know what is not a weed 2.Is it taking over the garden? 3.Is it outcompeting other plants for light and food?
13
Sometimes someone a little new to plants or gardening can get tricked. Describe any differences you see Jack in the pulpit
14
Poison Ivy Leaves of three (actually 3 leaflets) Each leaflet has a stalk The plant is a vine, growing up trees and walls Flowers are small with obvious petals Jack in the Pulpit Arisaema triphyllum 3 parted leaf (3 leaflets) Leaflets have no stalk The plants is terrestrial, growing up to 1 foot high only Flowers are big, no obvious petals
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.