One-flower Cancer Root (Aphyllon purpureum, formerly Orobanche uniflora var. purpureum) is a strange, diminutive plant that can be found in various parts of North America, typically inhabiting dry, sandy, or rocky habitats such as grasslands, sagebrush steppe, open woodlands, and coastal bluffs. A fully parasitic plant dependent on its host species, it attaches itself to the host plant via specialized penetrating roots called haustoria. Since all chlorophyll is derived from the host plant (native stonecrops, strawberries, and heucheras), One-flower Cancer Root produces no leaves, instead opting to produce a single flower per corm. While there is some debate over species phenology, we can confirm that this plant is at least a short-lived perennial under ideal conditions, producing a small corm that can persist for at least a few years, but may also occur as an annual.
 
One-flower Cancer Root typically blooms from late spring to early summer, with its peak bloom occurring from June to July. During this time, clusters of small, tubular flowers emerge from the ground, ranging in color from white to pale pink. Although individually small, the flowers collectively create a striking display and attract hummingbirds, small bumblebees, and small solitary bees. Often growing with stonecrops high on steep cliffs and bluffs, hummingbirds find the flowers attractive enough to linger at ground-level for the nectar.
 
Although adapted to a wide range of soil types, including sandy, loamy, or rocky soils, it requires chemical signals from suitable host plants, as well as mycorrhizal interactions, for successful germination and growth. The seeds of One-flower Cancer Root are tiny and dust-like, being dispersed through various means such as wind, water, or animal movement. Germination occurs when the seeds contact the roots of compatible host plants and establish a parasitic relationship. Lacking specialized propagation equipment, an effective approach is to lightly scratch into the upper root zone of established, low-growing Sedum specimens in late winter, evenly distribute a very small amount of seed, and gently water-incorporate into the soil. Plants may require a year or two to appear.
 
Due to its parasitic nature and high cultivation demands, One-flower Cancer Root is not recommended for beginning horticulturists, has limited landscape functions, and may not be suitable for most traditional gardening, nursery, or general landscaping purposes. However, in maintained xeriscapes and natural habitats, it contributes to the overall biodiversity and conservation value, while providing niche pollinator forage and ecological interest.