They have yellow or white-and-black striped bark and a large tuft at the tops which can be knitted into a Thneed. This tuft is typically a warm color, commonly red, orange, yellow, pink, or purple (which is rare). Truffula trees apparently give off the smell of butterfly milk. The tufts which are furry to the touch apparently are "softer than silk."
According to the Lorax, it takes ten months for a seed to germinate, ten years to sprout into a sapling, and another ten years to become fully grown. (Though the movie version tends to show a faster growth-pattern in the germation and sprouting phases, most likely because it's rare a seed is tended too with the hand of a human with a caring heart, but non-the-less, it still takes many years to grow to its full potential via how study the best trees are from the roots up).
They also bear a fruit which resembles grapes. This fruit forms the primary diet of the Bar-ba-loots.
Role in The Lorax
The Truffula Tree's role in the Lorax is a source of material required in creating a Thneed. It is unknown what the trunk of the tree is used for, but due to the smog of the thneed factory, it most likely was used for firewood.
- The truffula tree is based on a real species of tree in Elliot's house that Dr. Seuss saw when he traveled there with his first wife.
- The trees bear a faint resemblance to the clovers in Horton Hears A Who.