I took some time to get the terminology: radix tree/trie, patricia tree/trie ... it's all the same, really:

• A trie is a multi-way tree;
• I guess radix term replaced the Patricia appellation because it sounds more generic (not specific to information retrieval);
• And in the case of radix trie, if you use the binary representation of the key, you have an alphabet of 2 and the trie become a 2-ways tree, thus radix tree :P