Phillip, Asharrow would be a better source for specific numbers than I am, but I can tell you from experience (as well as the chart you posted, which was cool) that the differences in elongation potential between different species aren't huge. The differences in tensile strength, which to us= backs that don't break, is huge.
If you notice, the chart is for wood AND wood products, and while only a few are named, many others MUST be included in the main bubble. NO wood tested is outside bubble. See how the bubble for the wood"s numbers basically straddles 1% ? And see how on the far right edge the "stretchiest" wood product is paper (which is basically bonded felt made of wood-fiber, with fibers running every direction rather than parallel)?
Next note that BALSA, which is a ridiculous amount WEAKER than oak, stretches just barely less. Likewise, notice that oak stretched in it's STRONGEST dimension (along the fibers) stretches only about twice as far (+/- 2%) as when stretched in it's weakest dimension, across the grain (+/- 0.8-0.9%). So, even strong wood, in it's strongest tensile application, isn't very stretchy.
Though they weren't named, they must have tested other woods, but note how close oak is to the top of the bubble. This means that even woods much more dense and "stronger" (in other practical senses), than oak aren't a lot stronger than oak in perfectly longitudinal tension (break resistance). AND note that since paper, an engineered product, dominates the right side of that bubble, we can guess that those more dense strong woods don't ELONGATE much more than oak, either. Oak stretches only a smidgin more than pine and a tad more than balsa. I'm guessing ipe stretches only a tiny bit more than oak, then.
