how best to do a burning bush?

actually a burning tree, but general same idea. the problem is that most bushes and trees are created with alpha mapped planes to create the small branches and leaves, but when you intersect them with a smoke domain, it seems to do wonky z-depth masking of the smoke based on the geometry rather than the alpha. i’ve tried combos of z-transp and ray transp on both the smoke and leaf materials, but nothing appears to work. is there a trick i’m overlooking or is this a fundamental limitation of the volumetric shader?