Unlike winter squash, people often don’t know the varietal of the summer squash they are selling. I tried three from the farmer’s market that the sellers couldn’t identify- a yellow one with a bulbous end and light yellow stripes, a small green striped one, and a short, plump light green one. Looking at The Compleat Squash, my best guess is that the small striped one is Striato d’Italia and the plump green one is Costata Romanesco. That book didn’t have any striped yellow summer squashes, but a seed catalogue online has a similar looking hybrid squash called Sunbeam.
Yellow: not much flavour when raw. Grilled, it had a nice flavour but didn’t stand out from other squash I have had.
Small Green: buttery and delicious when raw. This one actually surprised me – I haven’t had a squash that tasted like this before. Grilled or sautéed it did not stand out from the other squashes, though.
Plump green: unpleasantly astringent when raw. Fine, but nothing special when grilled or sauteed.