The pattern is named for a fresh water aquatic plant Vallisneria, commonly called eel grass or tape grass. The KAL theme was "Biology" so I picked out this tonal green yarn from the stash and matched it up to this pattern for Vallisneria Socks by Jean Clement.
As written the pattern is knit on 2.75mm with a primary stitch count of 64 stitches. Breezing through the Ravelry projects, I noted a couple of mentions of the sock working up small. So I opted to add two pattern repeats and cast on 80 stitches and then shifted down to 2.25mm needles. I couldn't be happier with the result. The pattern is quite stretchy horizontally, so when worn it opens up nicely without being terribly stretched.
Just before starting the heel flap I purled together every instance of two purls stitches to bring the stitch count for the heel flap down from 40 to 30. I have pointy heels - narrower and longer heel flaps work best for me. I continued with gusset decrease until I had 30 sole stitches. Add those to the 40 instep stitches and the primary stitch count for the foot is 70 sts. That's on the high side for me, but seems to suit the pattern. When I reach the toe I'll employ the same decrease strategy to reduce the instep stitches from 40 to 30 sts before starting the toe decreases.
I'm actually amazed at how much I like these socks. I almost never repeat a pattern but with this one I just might. I'll admit that I still think the pattern's a bit pricey for what it is, but the fact that I'm so happy with the result goes a long way to making me happy with my purchase. That being said, I did have to do a lot of modification to get the fit where I wanted it, so that's not a great reflection on the pattern. Never mind all that though - awesome green socks!!!!