it's a leaf tube piped with a striped bag of icing (is it the 952 or something?)
i'd lay a stripe of green icing on the cake as if it were the stem
this will give the rounded look
when you pipe the starburst designs on top of it
start the starbursts around the sides then up the middle last
maybe it's 352
it looks like a v shape--not the 67 type
you can flatten the tip of a parchment cone and cut this tip too, snip the tip off in both directions
making a v shaped point--works great
Hyacinths have 6 points. Use an Ateco #844 pastry tube to make drop type flowers without twisting. Freeze or air dry and then apply them to heaps of the same icing above the leaves.
Thanks for the tips!