Because their growing points are near the ground, they are resistant to drought and fire. Examples include familiar wildflowers such as prairie dock, but not New Jersey Tea, which is a shrub. Woody plants are perennials that produce winter buds above the ground on over-wintering branches. Weeds - plants that are undesirable for any number of reasons.
Some weeds are alien plants that aggressively compete with native plants.
Others are native plants, such as brambles and tree seedlings, that threaten to convert the prairie to woodland.