1. Introduction

Habitat and Distribution

Roystonea altissima is endemic to Jamaica, where it naturally occurs in scattered populations throughout the island's mountainous interior and coastal lowlands. The species thrives in diverse habitats ranging from limestone hills to alluvial valleys, typically at elevations from sea level to 900 meters. It shows remarkable adaptability to both wet and seasonally dry forests, often forming distinctive groves in river valleys and on hillsides with deep, well-drained soils.

Native Continent

Scientific Classification

Synonyms

• Palma altissima Mill. (basionym)
• Roystonea regia var. altissima (Mill.) H.E.Moore
• Oreodoxa altissima (Mill.) Kuntze
• Roystonea jamaicana L.H.Bailey
• Euterpe altissima (Mill.) Spreng.

Common Names

• English: Jamaican royal palm, Mountain cabbage palm, Jamaican mountain palm
• Spanish: Palma real jamaicana
• Jamaican Patois: Cabbage palm, Royal palm
• Local names: Mountain royal, Swamp cabbage

Global Expansion

From its Jamaican origin, Roystonea altissima has been introduced to various tropical regions:

• Caribbean Islands: Cultivated in Puerto Rico, Cuba, Hispaniola, and Lesser Antilles
• Central America: Established in Costa Rica, Panama, and Honduras
• South America: Ornamental plantings in Colombia, Venezuela, and coastal Brazil
• Florida, USA: Limited cultivation in southern Florida (USDA zones 10b-11)
• Pacific Islands: Introduced to Hawaii, Fiji, and French Polynesia
• Southeast Asia: Rare in cultivation in Thailand and Singapore
• Indian Ocean: Specimen plantings in Mauritius and Seychelles

2. Biology and Physiology

Morphology

Trunk/Stem

Roystonea altissima develops a massive, columnar trunk reaching exceptional heights of 25-40 meters (82-131 feet), making it one of the tallest royal palms. The trunk is characteristically smooth, gray to white-gray in color, with a distinctive bulge at the base and sometimes a slight swelling in the middle section. Trunk diameter ranges from 40-70 cm at breast height. The surface shows regular ring scars from fallen leaves, spaced 10-15 cm apart.

Leaves

The crown consists of 15-20 massive pinnate leaves, each measuring 4-6 meters in length. The leaves arch gracefully, creating a full, rounded crown. Each leaf contains 200-300 pinnae (leaflets) arranged in multiple planes, giving a plumose appearance. Individual pinnae measure 60-90 cm long and 3-5 cm wide, dark green above and slightly lighter beneath. The petiole is relatively short (30-50 cm), merging into a prominent crownshaft.

Flower Systems

Roystonea altissima is monoecious with infrafoliar inflorescences emerging below the crownshaft. The branched panicle measures 1-1.5 meters long, enclosed initially in a woody, boat-shaped spathe. Male and female flowers occur on the same inflorescence, with male flowers more numerous. Male flowers have 6-9 stamens and are cream-white, while female flowers are smaller with a three-carpellate pistil. Flowering occurs year-round with peaks in spring and summer.

Life Cycle

• Germination phase (0-3 months): Rapid germination and initial root development
• Seedling phase (3 months-2 years): Establishment of first pinnate leaves
• Juvenile phase (2-10 years): Trunk formation and vertical growth initiation
• Adult vegetative phase (10-20 years): Rapid height increase, full crown development
• Reproductive maturity (15-20 years onwards): Regular flowering and fruiting
• Mature phase (20-100+ years): Continued growth and reproduction
• Senescence (100+ years): Gradual decline, susceptibility to wind damage

Climate Adaptations