Calyptronoma rivalis (O.F.Cook) L.H.Bailey, Gentes Herb. 4: 171 (1938)

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Map uses TDWG level 3 distributions (
Dominican Republicpresent (World Checklist of Arecaceae)B
Haitipresent (World Checklist of Arecaceae)B
Puerto Ricopresent (World Checklist of Arecaceae)B
Native to stream banks and arroyos in the hills and mountains of Hispaniola and western Puerto Rico. (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A


  • Cook designated no type for his Cocops rivalis, but the specimen at US collected by Underwood and Griggs the same year in which the name was published is annotated as the type by R. Read. I concur with his choice of lectotype. The type named by Wessels Boer (1968), Cook s.n., does not exist. Bailey designated two syntypes in his original description of C. quisqueyana. Bailey 229 is a fertile collection from a mature palm; whereas, Bailey 229a is a vegetative collection from a nearby palm that was specifically collected to supplement 229 ("Collected to show leaf tip"). The more complete collection, Bailey 229, is therefore taken as the lectotype.
    On Hispaniola, where this species co-occurs with C. plumeriana, the two species do not appear to flower at the same time. Data from herbarium specimens indicate that Hispaniolan populations are reproductively isolated.
    The calyptrate corollas of the staminate flowers, small fruits with adherent endocarps, and convex outer walls of the abaxial epidermal cells distinguish C. riualisfrom all other species
    (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A

Biology And Ecology

  • Phenology: Data from Puerto Rico are scarce but indicate that this species flowers in April. Fruit collections are known from May and August. In Hispaniola, flowers have been collected in October, December through February, and April. Fruits have been encountered in April, August, and November. (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A


  • The existence of. C. rioalis outside of Puerto Rico has some bearing on its conservation status. It has been listed as Threatened by the U.S. Fish and Wildlike Service since February, 1990. In Puerto Rico, this palm is confined to a small area, the type locality, between Lares and San Sebasti5n. Additional populations are said to exist in nearby watersheds (e.g., the Tanama River gorge [Little and Woodbury 1980]), but I have seen no specimens. Its continued protection in Puerto Rico is recommended. In Hispaniola, this species is found over a wide area from Haiti to eastern Dominican Republic. It does not appear threatened in Hispaniola. (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A

Common Name



  • Stem to 15 m tall. Leaf 3.1-5 m long; segments 54-107 cm long, 3-6 cm wide, glabrous on the abaxial intercostal surface. Prophyll 35-61 cm - long, 6-10 cm wide; penduncular bract 66-77 cm long, ca. 8.5 cm wide. Peduncle 39-77 cm long and 1.3-3 cm wide; rachillae 17-23(-26) cm long, 3.7-5.4 mm in diam., with 6(-7)'rows of pits; proximal rachillae borne in clusters of up to 3-5(-7) on stalks 1.4-5.2 cm long, 0.6-0.9 cm wide, clustered rachillae borne for 1/2-2/3 the length of the rachis; pits 2.4-3.5 mm long, 1.7- 2.9 mm wide, longitudinal distance between pits (lip to lip) 5.3-10.5 mm. Staminate flowers 4.8-5.1 mm long; sepals 3-3.6 mm long, 1.1-1.2 mm wide; petals completely connate; staminal tube 4.1-4.5 mm long, 1.5-1.6 mm wide; filaments 0.8-1.2 mm long; anthers 1.6-1.7 mm long. Pistillate flowers not seen. Fruit 4.6-7 mm long, 3.6-4.6 mm in diam.; endocarp adherent from seed, obscurely net-like; seed 3.8-4.9 mm long, 2.9-3.5 mm diam. (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A

Materials Examined

  • DOMINICAN REPUBLIC. EL SEIBO. Guamira, between Hato Mayor and Sabana de la Mar, Jiménez 4111 (US); l5 klm al N de Hato Mayor, 400 m, Liogier & Liogier 27738 (NY, UPR); 1.8 km S of El Valle on road to Hato Mayor, Arroyo Manacla, 135 m, Zona & Salzman 479 (FLAS, JBSD, RSA). SAN CRISTOBAL. l5-18 km NE of Bayaguana along Rio Comatillo, 50-100 m, Sanders et al. 1711 (pro parte) (BH, FTG); 8.5 km from Comatillo on road to Cruce de Pilacón at Arroyo Pilacón, 160 m, Zanoni & Mejia 16410 (JBSD, MO); along Rio Comatillo, Bayaguana, 150 m, Liogier & Liogier 21256 (NY); Liogier et al. 27564 (NY). SANTIAGO RODRIGUEZ. Monción, Cordillera Central, al sur de La Meseta, arroyo Manguanita, 485 m, Garcia et al. 2630 (NY). HAITI. OUEST. Near Saut d'Eau, ca. 300 m below waterfall, Henderson & Aubry I l85 (NY); Masif des Matheux, Mirebalais, Morne Saut d'Eau, ca. 400 m, Ekman H5498 (NY, S, US); Morne Saut d'Eau, above Ville Bonheur, Bailey 229a (BH). SUD. Morne de la Hotte, Ekman H167 (S). PUERTO RICO. Between San Sebastián and Lares, Bailey 45 (BH,MO), Britton & Hess (FI, GH, MO, NY, US), Liogier & Vivaldi 28727 (NY, UPR, US); valley about 4 km E of San Sebastián Horn s.n. (BH); near Camuy, Sintenis 6061 (US). CULTIVATED. PUERTO RICO. Rio Piedras, University of Puerto Rico Botanic Garden, Salzman 253 (spirit collection) (FTG). (S. Zona, A Revision of Calyptronoma (Arecaceae). 1995)A