Gourds are not poisonous to humans, although some types do have a bitter taste that make them very difficult to eat. According to Wildflower.org, there are four types of gourds, including the buffalo, fingerleaf, coyote and Okeechobee gourd, all of which are native to North America.
The buffalo gourd has a bitter taste that makes it inedible. Another plant in North America with gourd-shaped fruits called the balsam gourd is considered toxic; however it works primarily as a laxative if you eat the berries. This is not listed as being seriously toxic, and it is known only as having minor toxicity.