The women sit on stools for eight to ten hours a day scraping the spines away with small knives. Many of them seem elderly. One is sound asleep, hunched on her stool, knife still clutched in her hand. Mestizo women tend to be darker, more round-faced than other Mexicans here in San Miguel de Allende, and selling the cactus fruit is perhaps there only source of income. During my month-long stay, I have seen the cacti everywhere along the road from Guanajuato to San Miguel. This is painstaking work, or painful: the spines will stick in the soft flesh of your hand, break off, and take weeks to work themselves free.

One afternoon I stumble upon an exhibit in a local gallery, “The Heart of Frida.” Kahlo’s mother, Matilde Calderón y Gonzalez, was of primarily indigenous descent and Frida knew more than her share about painful spines. The exhibit is filled with small notes tucked away into boxes, poems and doodles on odd slips of paper, with titles like “Frida, the Crippled Eagle,” and “Diego, the Fat Amphibian.” The notes and pictures are overwhelmingly hopeless. In a poem titled “Wasting Away,” she compares her crippled body to the ash of a cigarette, waiting for Diego to flick her off, into eternity.

During my time in Mexico, I am surrounded by images of Diego Rivera, a circular man I am coming to resemble in my middle age. Rivera consumed human flesh; at least three times, he claimed, out of curiosity, feasting on cadavers purchased from the city morgue. So the least I could do, I thought, was to consume the flesh of the cactus. This wasn't so hard in the end, when I learned that the little green slices in my morning eggs were in fact nopales, or prickly pear. I had been eating them all along, without knowing. Still, I wanted more, and earned odd looks from the women in the market when I asked for a bag of round nopales with the spines not yet removed.

Frida’s crooked spine grew worse over the years, as did her love for Diego, as did Diego’s legendary infidelities. Frida progressed from unsent letters ending with “Diego, my great love, I am here, I await you,” to poems declaring that Diego the useless toad was only good for eating, “in tomato sauce.” She had gone full circle. Looking in a mirror for years, painting her own picture, she found beauty in her stern face and dark eyes, until Diego’s endless appetites made her hate what she saw.

In one of her late-life paintings, “The Circle,” Frida Kahlo depicts her own body, with missing limbs, and no head -- a woman disintegrating. Not unbroken. A few days before she died, she wrote in her diary: “I hope the exit is joyful -- and I hope never to return.”