Roystonea

Stems solitary, erect, greater than 20 cm in diam., smooth, unarmed. Leaves: leaf bases unarmed, forming crownshaft, crownshaft prominent, green, smooth; petiole unarmed; blade pinnate; plication reduplicate; segments linear-lanceolate, in more than 1 plane. Inflorescences axillary below crown of leaves, paniculate, with 2 or 3 orders of branching; prophyll tubular; peduncular bract greatly exceeding prophyll, leathery, splitting longitudinally on abaxial side and circumscissilly at base; rachillae covered with copious caducous dendritic trichomes, becoming glabrous. Flowers unisexual, sessile, in triads of 1 pistillate flower flanked by 2 staminate flowers. Staminate flowers: sepals 3, imbricate, membranaceous; petals 3, valvate; stamens 6(–10, rarely); anthers dorsifixed, often twisting upon drying; pistillode minute, obscurely 3-cleft. Pistillate flowers globose to conic; sepals 3, imbricate; petals 3, basally connate, distally valvate; staminodes 6, basally connate, adnate to corolla basally; pistil 1; ovules 1; style indistinct; stigmas 3. Fruits drupes, fibrous; stigmatic scar basal; exocarp ripening from green to red to purplish black at maturity, thin, leathery; mesocarp fleshy, oily; endocarp hard. Seeds 1, nearly globose [obovoid], dorsiventrally compressed, abaxially attached to endocarp; endosperm homogeneous; embryo basal; eophyll undivided, linear-lanceolate. x n = 18.

Distribution

Fla., Mexico, West Indies, Central America, South America.

Discussion

Most species of Roystonea are widely known as royal palms. They are cultivated worldwide and are especially favored as avenue trees. Long rows of gray-white columnar trunks are unmatched for their magnificence and stateliness. In some parts of the Caribbean, especially Cuba, Roystonea is a significant resource for thatch (leafbases only), timber, livestock feed, palmito (palm cabbage or heart-of-palm), and edible oil (F. A. Reynoso 1976; C. Ruebens 1968; T. A. Zanoni 1991; S. Zona 1991, 1996).

Species 11 (1 in the flora).

Selected References

Cook, O. F. 1936. Royal palms in upper Florida. Science, ser. 2, 84: 60--61.

Reynoso, F. A. 1976. Importancia económica de la palma real dominicana (Roystonea hispaniolana). Agroconocimiento 1: 8--9.

Ruebens, C. 1968. Industrialización del palmiche en Cuba. Industr. Alimenticia 1: 8--25.

Small, J. K. 1937. Facts and fancies about our royal palm. J. New York Bot. Gard. 38: 49--58.

Zanoni, T. A. 1991. The royal palm on the island of Hispaniola. Principes 35: 49--54.

Zona, S. 1991. Notes on Roystonea in Cuba. Principes 35: 225--233.

Zona, S. 1996. Roystonea (Arecaceae: Arecoideae). In: Organization for Flora Neotropica. 1968+. Flora Neotropica. 75+ nos. New York. No. 71, pp.1--36.

Lower Taxa

Roystonea regia