You can set the height, diameter, wall thickness, number of "arms or twigs", twist angle and direction.
Additionally you can add a hole or a small ring to hang the tree up.
And a base circle can be added as well.
Not the easiest print.
Adhesion to the bed should be no problem even when using only the small baseplate.
Whithout the foot (like philwild's original), I was not able to print without getting it knocked off. Contact to the bed would only be some 0.5 mm stripes in that case. With the small foot it is 5 mm stripes.
With my printer (Makergear M2) the noozle sometimes "makes contact" with on of the "fins" resulting in strange noises but it did not break the print.
The really difficult part is the top!
As the tree diameter gets smaller and smaller, the noozle keeps hovering more or less at the exact same spot, transferring a lot of heat down on the print.
At least with PLA, you will definitely need a fan, and set it to 100%. Maybe you even need to additionally blow yourself on the print. Don't faint!
It may help to print e.g. four of the trees of same size at once so the noozle moves away letting it cool. I did not try but others have used this technique for other small and high prints..