island desert-dandelion

Malacothrix squalida Greene

Malacothrix squalida is an annual herb in the Asteraceae family, native to Santa Cruz and Anacapa Islands in California. It is known as the island desert-dandelion and is federally listed as endangered. The plant grows on rocky seaside bluffs and cliffs, with a hairless, waxy stem reaching up to 30 cm in height. It was last collected from Santa Cruz Island in 1968 and has limited populations on Anacapa Island. The species is threatened by habitat degradation and environmental factors such as drought.

Description

Malacothrix squalida is an annual herb with a stem height of 4-30 cm, growing from 1-3+ stems that are ascending to erect and branched from the base. The leaves are obovate to oblanceolate, pinnately lobed, and glabrous. The involucres are campanulate, with 31-49 phyllaries in 56+ series. The florets are light yellow, with outer ligules exserted 6-11 mm. The cypselae are prismatic or columnar with 5 prominent ribs, and the pappi consist of 15-20 deltate teeth. The species is endemic to the Channel Islands of California and is critically limited in distribution, with populations only on Santa Cruz and Anacapa Islands.