Wilkesia gymnoxiphium A. Gray


Unbranched monocarpic rosette shrub or less frequently branched near the inflorescence (rarely near base) and polycarpic; the rosettes elevated on woody stems up to 5 m tall. Diagnostic features of the species 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. Flowering occurs mostly from May to July.

This species occurs only on Kaua'i, on dry ridges or in open sites in dry to mesic forests at elevations ranging from about 425-1,100 m. It is found in sites receiving about 80-200 cm precipitation per year.

Last Modification: March 28, 2000

Each "thumbnail" image below is linked to a larger photograph.

A population on the brink of Waimea Canyon at Iliau Loop Trail (photo 1978)
A particularly tall iliau with Robert Robichaux. Most individuals in the populations are unbranched and monocarpic (Iliau Loop Trail) (photo 1980)
Sometimes the leaves turn red before they drop, as in this striking individual.
Branched individuals like this one are not rare but comprise a low frequency in the populations.
A characteristic of the genus is the sheathing base of each whorl of leaves (photo 1983)
This photo shows whorls of bracts and rayless heads typical of Wilkesia (photo 1978)
This close view reveals a branching peduncle (photo 1981)
Close view of head, note the strongly coalesced peripheral receptacular chaff forming a cup-like false involucre.

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