The central vein is embroidered in outline stitch, you find it here.
Thread: 2 strands of Kreinik metallics pale green.
The lower half is alternating chain stitch also known as magic chain stitch.
I used one strand of olive green silk and one strand of med sage green.
It was difficult to change colors as both greens looked alike a lot.
This variation of the chain stitch turned out to be a TAST stitch in November 2012.
Along the upper half of the leaf I embroidered german knotted blanket stitch, you find it here.
Thread: 2 strands of Soie Cristal 5002 medium sage green
The whole picture