Here are the data structures with brief descriptions:

octomap::AbstractOccupancyOcTree	Interface class for all octree types that store occupancy
octomap::AbstractOcTree	This abstract class is an interface to all octrees and provides a factory design pattern for readin and writing all kinds of OcTrees to files (see read())
octomap::AbstractOcTreeNode
octomap::ColorOcTreeNode::Color
octomap::ColorOcTree
octomap::ColorOcTreeNode
octomap::CountingOcTree	An AbstractOcTree which stores an internal counter per node / volume
octomap::CountingOcTreeNode	An Octree-node which stores an internal counter per node / volume
octomap::equal_keys	Comparator for keys
octomap::hash_key
iterator_base	Base class for OcTree iterators
octomap::OcTreeKey::KeyHash	Provides a hash function on Keys
octomap::KeyRay
leaf_bbx_iterator	Bounding-box leaf iterator
leaf_iterator	Iterator to iterate over all leafs of the tree
octomap::MapCollection< MAPNODE >
octomap::MapNode< TREETYPE >
octomap::OccupancyOcTreeBase< NODE >	Base implementation for Occupancy Octrees (e.g
octomap::OcTree	Octomap main map data structure, stores 3D occupancy grid map in an OcTree
octomap::OcTreeBase< NODE >
octomap::OcTreeBaseImpl< NODE, INTERFACE >	OcTree base class, to be used with with any kind of OcTreeDataNode
octomap::OcTreeBaseSE< NODE >
octomap::OcTreeDataNode< T >	Basic node in the OcTree that can hold arbitrary data of type T in value
octomap::OcTreeKey	OcTreeKey is a container class for internal key addressing
octomap::OcTreeLUT	Implements a lookup table that allows to computer keys of neighbor cells directly, see: Samet 1989, "Implementing ray tracing with octrees and neighbor finding"
octomap::OcTreeNode	Nodes to be used in OcTree
octomap::OcTreeNodeStamped
octomap::OcTreeStamped
octomap::Pointcloud	A collection of 3D coordinates (point3d), which are regarded as endpoints of a 3D laser scan
octomath::Pose6D	This class represents a tree-dimensional pose of an object
octomath::Quaternion	This class represents a Quaternion
octomap::ScanEdge	A connection between two ScanNodes
octomap::ScanGraph	A ScanGraph is a collection of ScanNodes, connected by ScanEdges
octomap::ScanNode	A 3D scan as Pointcloud, performed from a Pose6D
iterator_base::StackElement	Element on the internal recursion stack of the iterator
octomap::CountingOcTree::StaticMemberInitializer	Static member object which ensures that this OcTree's prototype ends up in the classIDMapping only once
octomap::OcTreeStamped::StaticMemberInitializer	Static member object which ensures that this OcTree's prototype ends up in the classIDMapping only once
octomap::OcTree::StaticMemberInitializer	Static member object which ensures that this OcTree's prototype ends up in the classIDMapping only once
octomap::ColorOcTree::StaticMemberInitializer	Static member object which ensures that this OcTree's prototype ends up in the classIDMapping only once
tree_iterator	Iterator over the complete tree (inner nodes and leafs)
octomath::Vector3	This class represents a three-dimensional vector