Ptychosperma macarthurii

Common Name

Macarthur Palm

Description

Stems: Clustering, each stem with 8-10 leaves, slender, light gray stems to 8 m tall and up to 3-10 cm in diameter, with widely spaced, ridged leaf scar rings. Leaves: Pinnate, reduplicate, 1-2 m long, with a slightly arching rachis holding drooping, regularly arranged leaflets in a single plane. The crown shaft is about 50-60 cm long, somewhat swollen at the base, and light green with a waxy white coating. Leaflets are green above and below, widest toward the middle or wedge-shaped, prominent midribs with brown or tan twisted ramenta on the underside. Leaflet tips are truncated and jagged (praemorse). Flowers and fruits: Inflorescence is pendulous, to 60 cm long and with yellowish branches. White male and female flowers are borne on the same inflorescence. The ovoid, red fruits are 1-1.5 cm long and have remnants of the stigma at the apex.

Diagnostic Features

Slender, clustering, gray stemmed palms with pinnate leaves, a short crown shaft with a waxy white coating, and praemorse leaflets that are are green on both sides.

May be confused with

Ptychosperma elegans, but it is a taller, solitary palm with ascending rather than drooping leaflets.

Distribution

Native to southern New Guinea and northern Australia

Additional Comments

This palm is native to swampy areas, but is sometimes cultivated, including in Hawaii.

Scientific Name

Ptychosperma macarthurii (Wendl.) Nichols.

Family

Arecaceae/Palmae

Synonyms

Actinophloeus macarthurii (H. Wendland. ex J. G. Veitch) O. Beccari. ex Wigman

Kentia macarthurii H. Wendland. ex J. G. Veitch

February 15, 2011