Crabgrass

• Crabgrass has thick stems that radiate outward along the ground from the place where the plant emerges from the soil; wide leaves are sparsely distributed along the length of the stem and more densely at its end. The chaffy flowers grow in clusters at the end of long upright stems; the clusters look like slender fingers that radiate from a point.
  
  

Dandelion

• The yellow flower head of the dandelion turns into the white head of seeds.Dandelion image by Andrey Kobyak from Fotolia.com
  
  The dandelion has a sturdy taproot (a root that looks like a carrot) and a whorl of deeply-toothed basal leaves (leaves that grow next to the ground at the bottom of the plant). It has only one long bare, hollow flower stalk, and its yellow flower is a composite head (many little flowers growing compactly on the end of the stem and forming what looks like a single flower).
  
  

Plantain

• Plantain is a low-growing herb.plantain image by Aleksandr Popov from Fotolia.com
  
  Plantain is a low-growing herb consisting of ovate (egg-shaped) leaves on short stems that spring from the point where the plant emerges from the soil. The inflorescence (flower cluster) is a short spike, an upright stem with drab little flowers and later seeds that hug the upper half of the stem all around its circumference.
  
  

White Clover

• The white clover flower resembles this hop clover flower.pure white flower of hop-clover image by alri from Fotolia.com
  
  White clover has a short stems with a trifoliate leaf (three leaflets) at the end in an arrangement that looks something like the clubs in a deck of cards. Its flower looks like a jagged white ball on a short stem.
  
  

Yellow Wood Sorrel

• Wood sorrel has heart-shaped leaves.Woodsorrel (Oxalis sp.) in redwood forest in California image by Lars Lachmann from Fotolia.com
  
  Like clover, yellow wood sorrel has trifoliate leaves; but the three leaflets are cordate (heart-shaped) instead of round. The radially symmetrical flower has five yellow petals.
  
  

Sensitive Plant

• The sensitive plant, a weed on tropical lawns, has a thorny stem and a leaf with very small leaflets that look like fine-toothed combs and flowers that look like fuzzy pink balls. The leaflets fold up when touched so they are hard to see.