AGS221 ASSIGNMENTS

ANNUAL WEEDS

Weed species that completes its life cycle (seed to seed) within one growing season or one calendar year

1.      Datura stramonium (jimsonweed)

2.      Chenopodium ambrosioides (mexicantea)

3.      Commelina communis (dayflower, Asiatic)

4.      Cuscuta spp. (dodder)

5.      Lactuca serriola (lettuce, prickly)

6.      Malva neglecta (mallow, common)

7.      Matricaria matricariodes (pineappleweed)

8.      Medicago lupulina (medic, black)

9.      Ambrosia trifida (ragweed, giant)

10.  Brassica kaber (mustard, wild)

11.  Sicyos angulatus (burcucumber)

12.  Solanum ptycanthum (nightshade, eastern black)

13.  Sonchus asper (sowthistle, spiny)

14.  Sisymbrium officinale (mustard, hedge)

15.  Melilotus alba (sweetclover, white)

16.  Xanthium strumarium (cocklebur)

17.  Veronica peregrina (speedwell, purslane)

18.  Euphorbia maculata (spurge, spotted)

19.  Melilotus offincinalis (sweetclover, yellow)

20.  Conyza canadensis (horseweed)

PERENNIAL WEEDS

Perennial weeds are more of a problem because they can live for several years. They survive the winter by storing food in their roots. These roots make them harder to get rid of than annual weeds. Some are difficult to dig out and others spread underground.

1.      johnsongrass,

2.      buckhorn plantain,

3.      sagebrush

4.      Bindweed (creeping jenny)

5.      field bindweed,

6.      quackgrass,

7.      Canada thistle

8.      Broadleaved dock

9.      Mouse-ear Chickweed

10.  Selfheal

11.  Creeping Cinquefoil

12.  Dandelion

13.  Cats Ear

14.  Creeping Buttercup

15.  Birds-foot trefoil

16.  The Daisy

17.  Bindweed- available

18.  Campanula

19.  Brambles

20.  Cough Grass

BIENNIAL WEEDS

Weed species that completes its life cycle over two growing seasons.

1.      wild carrot,

2.      common mullein,

3.      musk thistle

4.      Hairy galinsoga

5.      Parsley

6.      Sweet William Dwarf plant

7.      Urticaceae

8.      dandelion

9.      American stinging nettle

10.  slender nettle

11.  tall nettle

12.  tall wild nettle

13.  wild nettle

14.  wallflower

15.  Clover

16.  Prickly lettuce

17.  wild carrot

18.  Daucus carota (carrot, wild)

19.  dandelion

20.  American stinging nettle

AUTOTROPHIC WEED

In plant kingdom there is a competition for habitat (biotop), nutrition (food), and reproduction. For autotrophic plants nutrition is guaranteed by formation of:

Leaves	chlorophyll + solar energy organic substances (sugar, starch etc.)
Roots	uptake of water and minerals anorganic substances

Examples are;

1.      Oxalis

2.      Crabgrass

3.      Bindweed

4.      Creeping Charlie

5.      Lamb's-Quarter

6.      Plantain

7.      Dayflower

8.      Velvetleaf

9.      Purslane

10.  Smartweed

11.  Canada Thistle

12.  Pigweed

13.  Quickweed

14.  Knotweed

15.  Pokeweed

16.  Black Medic

17.  Dock

18.  Fleabane

19.  Henbit

20.  Prostrate Spurge

PARASITIC WEEDS

A parasitic plant acquires nutrients through direct association with host plant rather than competing with the plants

1.      Pyrularia pubera

2.      P. pubera

3.      S. cassioides

4.      Seymeria

5.      Parentucellia latifolia (Orobanchaceae)

6.      Cassytha

7.      C. campestris

8.      S. asiatica

9.      S. hermonthica

10.  O. ramose

11.  O. cernua

12.  O. crenata

13.  Christisonia wightii

14.  Aeginetia

15.  Christisonia

16.  Amyema

17.  Dicaeum

18.  Theobroma cacao

19.  Dendrophthoe pentandra

20.  Tapinanthus bangwensis