SyntaxError: Unexpected Identifier (Generators in ES6)

I came up with this simple experiment after reading the documentation on generators from MDN:

var nodes = {
    type: 'root',
    value: [
        { type: 'char', value: 'a' },
        { type: 'char', value: 'b' },
        { type: 'char', value: 'c' },
    ],
};

function* recursiveGenerator(node) {
    if (node.type === 'root') {
        node.value.forEach(function (subnode) {
            for (var suffix of recursiveGenerator(subnode)) {
                yield suffix;
            }
        });
    }

    else {
        yield node.value;
    }
}

for (generated of recursiveGenerator(nodes)) {
    console.log(generated);
}

Running it on node.js v0.11.9 with the --harmony flag set produces the following error:

alix@900X4C:~$ node --version
v0.11.9
alix@900X4C:~$ node --harmony test.js 

/home/alix/test.js:14
                yield suffix;
                      ^^^^^^
SyntaxError: Unexpected identifier

I also tried using for ... in ... and the let keyword instead of var, but without any success.

I don't understand what yield* does exactly, but if I use it within the for loop I get instead:

alix@900X4C:~$ node --harmony test.js 

/home/alix/test.js:14
                yield* suffix;
                ^
ReferenceError: yield is not defined

If I replace the yield in the for with console.log() it outputs a, b and c. What am I doing wrong?

Edit

Here's a minimalistic generator, showing that node.js knows what to do with generators:

function* alpha() {
    yield 'a';
    yield 'b';
    yield 'c';
}

for (var suffix of alpha()) {
    console.log(suffix);
}

Output:

alix@900X4C:~$ node --harmony y.js 
a
b
c

Solution (thanks @Andrew)

function* recursiveGenerator(node) {
    if (node.type === 'root') {
        for (var i = 0; i < node.value.length; ++i) {
            var subnode = node.value[i];

            for (var suffix of recursiveGenerator(subnode)) {
                yield suffix;
            }
        }
    }

    else {
        yield node.value;
    }
}

for (generated of recursiveGenerator(nodes)) {
    console.log(generated);
}