Watermelons seeds are roasted by Asians. Pickled watermelon rind is also popular.
Until the 1940s, a good watermelon was rarely found in a grocery. Melon lovers had to grow their own, which, sadly, wouldn't keep for long.
Then a USDA plant breeder set out to produce a better watermelon. The result was "that gray melon from Charleston," formally called the Charleston Gray. Its oblong shape and hard rind made it easy to stack and ship. Its adaptability meant it could be grown over a wide geographical area. It produced high yields and was resistant to the most serious watermelon diseases, anthracnose and fusarium wilt. Best of all, it tasted terrific. Today, almost all watermelon varieties have some Charleston Gray in their lineage.
This common watermelon is large enough that groceries often sell half or quarter melons. There are also some smaller, spherical varieties of watermelon, both red- and yellow-fleshed. So-called "seedless" watermelons have far fewer, and softer, seeds than average, but generally contain at least a few whitish seeds.
For commercial plantings, one bee hive per acre is the minimum recommendation by the US Department of Agriculture for pollination of conventional seeded varieties. Seedless hybrids have sterile pollen and pollinizer rows of varieties with viable pollen must also be planted, and the pollinator populations increased to three hives per acre.
The watermelon slice is striking and unmistakable in appearance. In former times, African Americans were depicted in racist caricatures as being inordinately fond of watermelon. The image of the watermelon, allusions to eating watermelon, and so forth, may still be seen as offensive. The historical perspective is that watermelons are native to Africa, and their seeds and culture was brought to the US, and taught by Africans.