Knotted Leaves

Proliferation of tissues occurs at leaf veins. Extra cell division makes knots appear near leaf collars (Neuffer, Coe, and Wessler, 1997).

Close-up of leaves with extra tissue and growth makes the leaves bend unnaturally.
Knots and tissue growth distort plant.
Extra tissue growth makes the traditional parts of a corn stalk almost unidentifiable.
Extreme symptoms.
View of the top of a plant shows a curvy, thick tassel growing out of the twisty extra volume of green leaves
Tassel that has emerged from twisted leaf sheath. Tassel should be normal, but is affected by tight sheath.
Close-up looking down on the leaf collar shows extra growth that adds crinkled volume to the leaves and looks like lettuce leaves
Close-up of leaf collar region with excess tissue growth.
Close-up of the lower part of the leaf shows the outside of the leaf covered in bumpy protrusions
Lower surface of mid-vein.
Close-up of upper surface of mid-vein shows black specks surrounding the bumpy knobby growths at the vein
Upper surface of mid-vein.