Ptychosperma macarthurii: Macarthur Palm

Edward F. Gilman, Dennis G. Watson, Ryan W. Klein, and Deborah R. Hilbert


Introduction

This attractive small palm is noted for its multiple, slim, ringed grey trunks which are topped with soft green, feathery, flat, broad leaves with tips that appear jagged and torn. Although able to reach 30 feet in height, Macarthur palm is most often seen 10 to 15 feet in height with a variable spread. The two-foot-long, branched flower stalks hang below the crownshaft throughout the year and contain small, white blooms. These blooms give way to bright red, showy sprays of half-inch-long fruits which ripen year-round.

Middle-aged Ptychosperma macarthurii: Macarthur palm.
Figure 1. Middle-aged Ptychosperma macarthurii: Macarthur palm.
Credit: Stephen Brown, UF/IFAS

General Information

Scientific name: Ptychosperma macarthurii

Pronunciation: tye-koe-SPER-muh mack-ar-THUR-ee-eye

Common name(s): Macarthur palm

Family: Arecaceae

USDA hardiness zones: 10B through 11 (Figure 2)

Origin: not native to North America

Invasive potential: not considered a problem species at this time, may be recommended (North, Central, South)

Uses: indoors; deck or patio; specimen; container or planter

Range.
Figure 2. Range.
Credit: UF/IFAS

Description

Height: 15 to 25 feet

Spread: 6 to 10 feet

Crown uniformity: irregular

Crown shape: palm, upright/erect

Crown density: open

Growth rate: moderate

Texture: medium

Foliage

Leaf arrangement: spiral (Figure 3)

Leaf type: odd-pinnately compound

Leaf margin: entire, incised

Leaf shape: obovate, oblong, linear

Leaf venation: parallel

Leaf type and persistence: evergreen

Leaf blade length: 8 to 12 inches

Leaf color: green

Fall color: no color change

Fall characteristic: not showy

Foliage
Figure 3. Foliage
Credit: Stephen Brown, UF/IFAS

Flower

Flower color: white/cream/gray

Flower characteristics: not showy

Fruit

Fruit shape: round, oval (Figure 4)

Fruit length: 0.5 to 1 inch

Fruit covering: fleshy

Fruit color: red

Fruit characteristics: does not attract wildlife; showy; fruit/leaves not a litter problem

Fruit
Figure 4. Fruit
Credit: Stephen Brown, UF/IFAS

Trunk and Branches

Trunk/bark/branches: branches don't droop; showy; typically multi-trunked; thorns

Pruning requirement: little required

Breakage: resistant

Current year twig color: not applicable

Current year twig thickness:

Wood specific gravity: unknown

Culture

Light requirement: full sun, partial sun or partial shade, shade tolerant

Soil tolerances: clay; sand; loam; slightly alkaline; acidic; well-drained

Drought tolerance: high

Aerosol salt tolerance: low

Other

Roots: not a problem

Winter interest: no

Outstanding tree: no

Ozone sensitivity: unknown

Verticillium wilt susceptibility: resistant

Pest resistance: resistant to pests/diseases

Use and Management

Macarthur palm is often used in planters or urns but quickly outgrows these containers. It makes a striking lighted nighttime specimen, and is ideal for accenting shaded, sheltered locations, such as entranceways and patios. It is often planted in groups with individual trees several feet apart.

Macarthur palm prefers partial shade but will tolerate full sun or dense shade on any well-drained soil. Abundant moisture will allow it to look its best because it will keep more leaves.

Propagation is by seed.

Pests and Diseases

No pests or diseases are of major concern. This palm is lethal yellowing-resistant. Sooty mold sometimes coats the trunk.