I would increase the distance between segments even more. If you look at the ref, you'll find that the distance between segments is several times the diameter of the stem.
On the distant/thinnest stalks, the seams stick out too much, even though it's just one pixel. In those, I think it would look better to have a completely flat silhouette, and to only show the seams with colours.
On the left sides of the nearer stalks, the seam looks too prominent because it appears to stick out more, since the seam is all lit while the rest of the stem isn't. Shading those sticky-out parts so that they're closer in style to the stems should help.