Ask-a-Dave's-Gardener: Unidenified Volunteer, 0 by RedStraw

RedStraw wrote:
Near the end of this past spring, I had two volunteer plants pop up in the corner of my small garden. I\'m always curious about what\'s coming up on it\'s own so if I have the room for it I\'ll let it do it\'s thing. It looked like some sort of squash/gourd or possibly a melon. A ground crawling vine, with squash-looking blossoms. The excessive heat here in Southern California has really cooked the garden and I hadn\'t really been taking care of the mystery vine, so when it started going in to decline, I decided to rip it out. Only one fruit had survived the summer heat. I thought it was perhaps a buffalo squash, endemic to the area, but it doesn\'t seem to the characteristics of Cucurbita foetidissima, nor did the leaves resemble Cucurbita foetidissima\'s foliage. So, I have this fruit and have no idea what it is. It had small spikey hairs on it before I brought it in and washed it up; the fruit is about 4 inches [10cm] across. I have not cut it open just yet, thinking I\'d ask the community first and perhaps enjoy having it as is for a short while. Will cut it open in a day or two and share another photo with you all.