can dried bracken replace straw in cob

I'm trying to think of a plant which dries naturally in the fall in the Pacific Wet Coast area that would substitute for straw in cob. I'm thinking that bracken might fit the bill, but thought I'd ask if any permies have tried it. I'm thinking in terms of a small project like a rocket stove. Any other suggestions?

Bracken might have an excess of leafy material in ratio to the hard stock in the center. I know in the cob web from cob cottage quite a few people have used pine straw as a substitute. It tends to make more brittle cob, but even so I think it would work. If you could scythe down some tall grasses instead and let them dry, that would work just as well as straw. I don't know how close you are to the beach but I know someone used kelp strands from the beach to cob.