Foliage, with a number of modifications of my own, of course.
For starters, this hat is not knit with bulky or worsted-weight yarn as the pattern calls for, but with the leftover Mediumweight Socks That Rock from my Leafling socks. That makes it a heavy fingering weight yarn, just short of DK. I did several gauge swatches, and put my math to use figuring out how to make this work.
I didn't have enough leftovers to double the yarn and knit as written, plus I was really hoping to take advantage of the very pretty color-shifts which I hoped would stripe. I could knit the pattern as written, but on US3s, and come up with a child's hat. The original states its finished size as 17" stretching to 24" (that's a dang stretchy hat!). My guestimating put the as-written-but-fingering-weight-version at about 15" (or less) but stretching back to 19".
My other option was to expand the crown chart, which I ended up doing in a spreadsheet. I ended up with 33 stitches per needle, down to 32 stitches per needle after the last row of the crown (you decrease one stitch per needle on the very last row--a detail I almost overlooked when reading the pattern). I repeated the lace-pattern three times for the body of the hat and... ran out of yarn!
Rather than reknit the whole hat, I worked one round where every five stitches or so, I dropped one down and fixed my s1k2psso to the original decrease I used.
One more repeat of the lace pattern and I started the ribbing. For a while I toyed with doing a k2p2 rib. I really am not a fan of the "look" of a k1p1 rib. In the end I decided to stick with the pattern, mostly. I ended up extening the decreases of the lace-pattern into the ribbing. It's subtle but looks nice.
The body of the hat is just a tad long, but looks nice rolled in the front, framing my face a bit better than just a round-fit hat. I'm really pleased with the outcome and looking forward to sending my yarn-angel a little gift in thanks!