a·ris·ta 
(ə-rĭstə)
(ə-rĭstə)n. pl. a·ris·tae (-tē) or a·ris·tas
A bristlelike part or appendage, such as the awn of grains and grasses or the process near the tip of the antenna of certain flies.
[Latin, beard of grain, spike.]
a·ristate (-tāt) adj.