Matter produced by plants or growing in the manner of a plant(noun)
WordNet. Princeton University. 2010.
Use "vegetable matter" in a sentence
"I come gladly to the conclusion that the megapode is a sagacious bird, not only in the avoidance of the dismal duty of incubation, but in respect of the making of those great mounds of decaying vegetable matter and earth which perform the function so effectively."
"The corpselike plant derived nourishment from decaying wood and vegetable matter since it lacked chlorophyll, and its waxy-looking surface turned black when touched."
"While his host hunkered over the diminutive adobe hearth, Alobar sniffed at the various braids of dried vegetable matter that hung against the walls, each broadcasting a different version of internal conditions within the plant kingdom, and he fingered the bones, fangs, and snail shells that, like chimes to be rung by the shaman's heavy breathing, dangled from the ceiling."