ROYSTONEA

Roystonea O. F. Cook, Science, Ser. 2, 12: 479. 1900; Fl. North Amer. @ eFloras.org 22: 116; Malik, Fl. Pak. @ eFloras.org p. 27.

Solitary, trunk up to 40 m or more in height. Stem erect, annular with prominent annular rings, smooth, stout, unarmed, swollen at base. Leaves pinnate, very large, glabrous; petiole stout, concave-convex, unarmed, petiole base enlarged into nearly close sheath which envelopes the stem, such leaf sheaths together form a smooth green ‘crown shaft’ at top of stem; leaf blade 1-pinnate, divided into many leaflets borne in more than 1 plane, pinnae linear-lanceolate, narrowly pointed, plication reduplicate. Inflorescences axillary below the 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 circumscillay at base; rachillae covered with copious caducous dendritic trichomes, becoming glabrous. Flowers unisexual, sessile, in triads of 1 female flower flanked by 2 male flowers. Male Flowers: Sepals 3, imbricate, membranous. Petals 3, valvate. Stamens 6-12, exserted; anthers dorsifixed, often twisting upon drying; pistillode minute. Female Flowers: Globose to conic; sepals 3, imbricate. Petals 3, basally connate. Staminodes 6, basally connate, adnate to corolla basally. Pistil 1, ovary 1-3-locular, ovules 1 per loculus; style indistinct, stigmas 3. Fruit drupe, red, small, oblong to rounded, up to 1.25 cm long; exocarp thin, leathery, mesocarp fleshy and endocarp hard. Seed 1, +/- globose, dorsiventrally compressed, abaxially attached to endocarp; endosperm homogeneous.

10 species

Roystonea regia

Roystonea regia (Kunth) O. F. Cook, Science, Ser. 2, 12: 479. 1900; Fl. North Amer. @ eFloras.org 22: 117; Malik, Fl. Pak. @ eFloras.org p. 28; Oreodoxa regia Kunth, Nov. Gen. Sp. 1: 305. 1816.

Solitary; stem up to 20-30 m in height and ca. 40 cm in diameter, erect, stout, greyish-white, smooth, unarmed with prominent rings of leaf scars; trunk thickened at base and nearly in middle (below crown shaft). Crown roundish, leaves up to 15 in a crown, up to 4 m long, drooping; leaf blade divided into numerous leaflets, leaflets in more than one plane; pinnae 60-80 cm x 2.5-3.5 cm, gradually reduced towards apex and base, linear-lanceolate, narrowly pointed, plication reduplicate, rachis tapering towards apex. Petiole up to 50+ cm long, stout, concave-convex, unarmed, glabrous, smooth, enlarged into leaf sheath at base; leaf sheath long, nearly close, the leaf sheath together form smooth, green, shining ‘crown shaft’, 1.5 m or more in length.

Inflorescence never observed in the area.

Common Names: Royal Palm, Bottle Palm, Cuban Royal Palm, Florida Royal Palm