Echinulate
Echinulate is an adjective describing the spiny, or "spiky" nature of some spores found in plants and fungi; an example is the auxiliary cell. The words derives from the same root as the prefix echino, meaning that the shape is similar to the porcupine (whose family name is Echinoprocta).
Source: adapted by the editor from Wikipedia, the free encyclopedia; from the article "Echinulate". Image Credit.