When I was in the third grade, our family moved to Nouasseur Air Base, near Casablanca, Morocco. Much of the local vegetation was low-growing scrub, but the gardens of city parks, private villas, and military housing were filled with colorful and dangerous plants and flowers. Thorny Bougainvillea vines spilled over garden walls in shades of purple and magenta. Poinsettia and oleander grew in gardens where children played. Cacti were common garden plants.

My mother loved cacti, and she had a tall, wicked looking one with needle-sharp spines in our front yard. Burton, one of neighborhood kids, told my mom, “One day I’m going to jump over that cactus.”

My mom responded, “If you do, you will be sorry.” One day, Burton jumped my mother’s cactus, and he was very sorry.

The species of cactus that grows on the Middle Peninsula is Opuntia humifusa, also known as Opuntia compressa, the Eastern Prickly Pear. It is native to eastern and central North America, from Ontario to Florida, and...