This is a stem of a two year old Portuguese galega (very similar to walking stick kale) that I culled from my breeding
project last year. I'm selecting for the ability to survive going to seed, so I let them seed and anything that doesn't survive is automatically weeded out, then the following year I breed from whatever survived.
The woody bit around edge is very hard, as you can see from the burn marks from the table saw that I cut it with. The centre is very soft, almost hollow. It had bark on it, but I used this bit to practice whittling bark off, so it's all bare now.
This one is a four year old plant which is seeding for the third time.
Its stem is turning into a veritable trunk! I have no idea if it will survive a third seeding, but when it finally shuffles off this mortal coil I intend to cut that trunk and see how wide it ended up and what percentage is wood and what is hollow.
Watch this space. I may be some time...