Curtiss's milkweed is a state-listed endangered species with specialized habitat requirements. It is found almost exclusively in scrub habitats where it tends to favor areas of pure sand with very little vegetation. It is remarkable in that it is one of the few plants that readily colonizes areas of pure sand at the edges of stable blowouts.
Geologically, a blowout is a depression in a sandy habitat caused by strong winds. Blowouts get their start when some disturbance, such as fire, extended drought, off-road vehicles, or human or animal foot traffic, results in the loss of protective vegetation. Sometimes, a positive feedback cycle forms where the blowout causes plants to die along its periphery, this makes the blowout bigger, and this in turn causes more plants to die, resulting in an ever expanding area of pure sand devoid of any vegetation.
Curtiss's milkweed occurs as a native plant only in the State of Florida. Within the state, it has a wide range and has been recorded in many counties from Clay County in the north to Broward and Collier counties in the south; however, it is endangered in spite of its wide distribution because of its exacting habitat requirements and habitat loss.
© 2010 Rufino Osorio.