Opuntia humifusa late spring. The juicy and edible red fruits measure from 3–5 cm. As the fruit matures, it changes colour from green to red, and often remains on the cactus until the following spring. There are 6 to 33 small, flat, light-colored seeds in each fruit. This species was originally native to arid areas of Montana southward to New Mexico, and eastward to the lower Great Lakes, and along the East Coast from the Florida Keys to coastal Connecticut. Some botanists treat this cactus as a variety of "Opuntia compressa": hence "Opuntia compressa" var. "humifusa", or a synonym of "Opuntia compressa".
Opuntia ficus-indica the plants are used as fodder. In these cases, the spines need to be removed from the pads to avoid damage to the animals. Mostly, this is achieved by burning the spines off the pads. "Opuntia ficus-indica" for human and animal consumption is its water content in an arid environment, containing about 85% water as a water source for wildlife. The seeds contain 3-10% of protein and 6-13% of fatty acids, mainly linoleic acid. As the fruit contains vitamin C (containing 25–30 mg per 100g), it was once used to mitigate scurvy. "Opuntia" contains selenium. The red color of the