Improved end dividers and headers of an agricultural harvester are disclosed. The end dividers are connected to a harvesting reel of a header such that fore and aft translational movement of the harvesting reel results in corresponding translation of a leading part of the end dividers. The result is an assembly that is effective for harvesting crops of differing heights and conditions without need for substitution of differently sized, fixed length end dividers. The end dividers may be secured to a header frame such that the end dividers float over uneven terrain. The end dividers can also include extensions or shrouds for receiving and protecting the ends of the reel, as well as sockets at their tips for releasably attaching various types of harvesting fixtures.