As a child, I often made spring wildflower bouquets, but was always told to avoid picking the mariposa lily blooms, since the entire plant would die if its flowers were picked. This seemed somewhat dubious to me, but the well-respected Plants of Southern Interior British Columbia corroborates my mother’s advice. I am unsure whether Calochortus tiburonensis is also fatally damaged by picking its blooms, but I do know that harvesting this threatened species is illegal under the California Endangered Species Act.
Calochortus tiburonensis is endemic to one small serpentine outcrop: Ring Mountain on the Tiburon Peninsula. Ring Mountain is ecologically unique, possessing an unusual climate and serpentine soils, which are toxic to most plant species but are the only soils in the entire world where Tiburon mariposa lily grows. The area around Ring Mountain is heavily developed, and an accidental discovery may be all that kept the entire population of Calochortus tiburonensis from being bulldozed to create another residential development. In this article (PDF), Robert West describes how he discovered the Tiburon mariposa lily while walking along Ring Mountain in 1971.
Calochortus tiburonensis is a perennial that grows from a bulb and reaches 10-60 cm in height. It forms a single leaf at the onset of winter rains, and then two to seven erect flowers in the spring. The flowers each have three petals that are light-green and streaked with purplish-brown. The petals resemble cat’s ears, both in shape and because their inner surfaces are covered in white, curly hairs. Each flower also has three pointy sepals, a three-pronged stigma, and six beautiful dark red stamens. When viewed from above,