Hello!
First of all, I am glad to be here on this great forum! While I am no botanist, and I don't know any plant lingo, hopefully I won't sound too ignorant.
On October 31, 2015, I was walking In a neighborhood nearby when I saw a vine plant growing in the ditch with some fruit on it. So I cut a few of them off and brought them home. I then cut a few of them open, scooped the seeds out, and put the seeds in multiple paper bowls. I spent the next couple months trying to find out what they were on the Internet, but to no avail.
Then when spring came around I planted the seeds all over my property for fun to see whether or not they would grow. I planted a few in a deep tire track near a small man-made pond.
Then fast forward to the middle of July. I was walking by the old tire tracks when I saw the plant growing in it. I got curious about it again.
The plant is in a small field so it gets direct sunlight for almost all of the day. I watered it with about a gallon (I guess) of water in the morning almost everyday, but that still was not enough. I have to water it with about 2 gallons in the morning and in the evening; 4 gallons a day.
Here is a basic description of the plant and its fruit:
-It is in the north Texas area. Hardiness zone 8a.
-The leaves have no smell to them (unlike to Buffalo Gourd).
-The flowers have five petals and are quite small (as seen in the pictures below).
-The fruit has a fruity/watermelon smell to it. Quite strong even when not cut open.
-The fruit is very smooth.
-The plant needs quite a bit of water or it has a hard time.
-The vine its self is very prickly and hurts to hold on to.
-The soil it grows in is full of rocks and isn't very deep.
-It doesn't seem to mind being in direct sunlight.
The pictures will tell the rest.
I hope this information will help to ID it! I have been searching everywhere (especially on the USDA plants website) but to no avail. If you need anymore pictures or need anymore details feel free to ask.
Anyways, here are the pictures. They were all taken on August 16 around 6:15 to 6:45 p.m. CDT.
(The measuring line is about 3' 10" long)
I don't even know when the fruit fully ripens.