Wilkesia gymnoxiphium (Hawaiian iliau), is a species of flowering plant in the family Asteraceae that is endemic to the island of Kauaʻi in Hawaiʻi.

[4] The members of these three genera constitute what is called the silversword alliance, a group whose exceedingly close genetic heritage is not reflected in their exceptionally diverse morphologies.

Distinctive features include a usually unbranched, monocarpic axis, leaves in whorls of 9–15 that join to form a basal sheath around the stem, and peduncles that are commonly branched.

It grows at elevations of 425–1,100 m (1,394–3,609 ft) in areas that receive 800–2,000 mm (31–79 in) of annual precipitation.

However, a dense population can be seen in a fenced enclosure just off the road heading to Kōkeʻe State Park.