Bamboo is very distinctive looking.....tight at the bottom and spreading out at the top with individual canes appearing. All that is visible in your last pic. If you look closely in your last view of the grouping you posted, you can see a lay-down on the right side of SI (shows up as a brush pile in 2D view), and what might be bamboo on the left SI. So it may be that is the pic with the Bamboo? I'm guessing you were in the same area?

There is also a spot nearly off the screen on left side SI that has the shape of bamboo and some corresponding vertical lines on right side SI. That might be the 'boo