elkhorn coral 
noun
A coral with sturdy antler-like branches, found in shallow waters throughout the Caribbean.
- Acropora palmata, order Scleractinia.
- The same disease had eliminated the elkhorn coral which should form a natural breakwater for Caribbean shores.
- Although later research showed it to be contagious, white pox appears to strike only one kind of coral - ‘the magnificent branching elkhorn coral,’ known as the ‘giant redwoods of the reef,’ said Porter.