The following was coppied from Tim Bakers bow wood list.
SCOTCH BROOM is a yellow-flowering little bush that grows along the roadways of California, watered by runoff from the crowned streets. It’s like countless other such plants, in that at first glance it seems more like a useless weed than the makings for an first-class bow. There are surely scores of such unsung shrubs waiting to sling arrows as well as the known woods if just given a chance. Scotch Broom is a great little bow wood. Dense and tough. If any size at all it tends to be twisted and gnarly. This wood tends to check easily when drying, so treat it like plum. Use trunks as narrow as 1” in diameter. Two such “trunks” spliced together at the grip will yield a 66” or so bow. The high crown will be safe, the resulting low mass only improving cast. The narrower the limb the longer the bow should be. But sub 48”, even 36”, self staves make evil little “Indian bows, the shorter ones limited to 40lb with drawlengths just under half of bow length. 50lb-plus, and stronger draws, can be gotten from mid-50” and longer bows.