Mexican Passionflowers (Passiflora mexicana) are beautiful, tropical-looking, native vines with bizarre flowers that almost look like something from an alien planet.

Mexican Passionflower's green flowers have 5 large, green sepals, yellows centers, and rings of fleshy filaments that start out a dull red color, but later fade to violet.

These flowers not only look strange, they smell strange as well. Mexican Passionflower flowers smell like mothballs, and the moist, shady gully in Tucson where I found several of these vines flowering was filled with their weirdly non-flowerlike, chemical odor. Mexican Passionflowers normally bloom anytime from July to September.

Even when not in bloom, Mexican Passionflower vines can be identified by their distinctive, round-tipped, bilobed leaves.

Despite the smell of their flowers, Mexican Passionflower vines are not poisonous and have been used effectively in herbal medicine as a gentle, natural sedative.