I know that the Chumash and Pomo indians used reed for their arrows, so if you can find some of that, it works really well. I remember when I was driving down I-5 from Oregon to San Francisco 4 years ago I kept seeing big, open areas with huge patches of reed/cane growing along the highway. Some if it was really big, much too big for arrows. I did stop, but the reed I examined was too large for arrows, so I didn't cut any. But if you find smaller shoots, reed works great. It's like bamboo, but with thinner walls.
Hell, just about anything straight will make arrows. I don't know about Oleander since I live in GA, but the way everyone keeps talking about it, it sounds like bad news. I've got an idea! You could cut some oleander, peel the bark and try eating it. If you die, well, then I guess everyone would be right!! Hahaha! (just kidding about eating the bark, of course)