Wilkesia gymnoxiphium

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Wilkesia gymnoxiphium
Wilkesia gymnoxiphium growing in Limahuli Garden and Preserve
Scientific classification
Kingdom: Plantae Division: Magnoliophyta Class: Magnoliopsida Order: Asterales Family: Asteraceae Genus: Wilkesia Species: W. gymnoxiphium
Binomial name
Wilkesia gymnoxiphium A.Gray

Wilkesia gymnoxiphium (Hawaiian iliau), also sometimes called a "green sword" is a species of Wilkesia native to Kauai, Hawaii. It is a descendant of the North American tarweed. Other descendants include the Halakala silversword and the Dubautia species.

Wilkesia gymnoxiphium is an unbranched monocarpic rosette shrub, with rosettes elevated on woody stems as much as 5 meters tall. Distinctive features include a commonly 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. Fountains of yellow, daisy-like flowers form mostly May to July.

This species occurs only on Kauai, on dry ridges or dry to mesic forests. The most common location is along the slopes of Waimea Canyon. Elevations range from about 425-1100 meters, with precipitation ranging from 80-200 cm per year.

Heavily grazed by feral goats in the canyon, they are most often seen on inaccessible slopes. However, a dense population can be seen in a fenced enclosure just off the road heading to Koke'e State Park.