A Revision of the Genus Anthurium (Araceae) of Mexico and Central America. Part I: Mexico and Middle America

Anthurium (Araceae), a distinct neotropical genus with more than 700 species, is a member of the subfamily Pothoideae. The genus ranges from Northern Mexico and the Greater Antilles to Southern Brazil and Northern Argentina and Paraguay. Species diversity is greatest at lower to middle elevations of northern South America, Panama, and Costa Rica, while the upper Amazonian forests and lower Amazonian forests are relatively poor in species. In this paper, 122 species from Mexico and Middle America are revised. The 152 Panamanian species will be treated in a subsequent paper. In Mexico and Middle America, Costa Rica is richest in species, with 65. The remainder of Middle America is relatively poor in species, with Nicaragua having only 25 known species, Honduras having only 13 known species, Guatemala having 25 known species, and Belize fewer than 10 species. Mexico has 41 known taxa with 26 species endemic. In all, six new taxa from Mexico and Middle America were described in this revision: A. armeniense, A. chamulense Matuda ssp. oaxacanum, A. halmoorei, A. lancetillense, A. nelsonfi, and A. rzedowskii. In addition, five new combinations have been proposed, including A. chiapasense ssp. tiaxiacense (Matuda) Croat, A. cuneatissimum (Engler) Croat, A. pedatoradiatum ssp. helleborifolium (Schott) Croat, A. schlechtendalii ssp. jimenezii (Matuda) Croat, and A. subcordatum ssp. chlorocardium (Standl. & L. 0. Wms.) Croat. Anthurium, a neotropical genus with more than 700 species, is a member of subfamily Pothoideae. Pothoideae contains ten genera, with only Anthurium and Heteropsis occurring in the American tropics. The Pothoideae is tropical, except for the tribe Acoreae, which contains the widespread genus Acorus and the Australian endemic Gymnostachys. The tribes Culcasieae and Zamioculcaseae with 26 species are strictly African. Four Asian genera, Pothoidium, Anadendrum, Pothos, and Pedicellarum, account for eight percent of the species of the subfamily. Only Pothos, with about 50 species, is very large. Araceae contains 110 genera and more than ' This study was completed with support from National Science Foundation grant DEB 77-14414. The revision was based on field observations in Mexico and Central America during 1976, 1977, and 1979 and on studies in Panama since 1967. In addition, all but 12 of the 122 species are in cultivation at the Missouri Botanical Garden, and extensive observations on these living collections have been carried out. I acknowledge the assistance of D. Nicolson, who reviewed the manuscript, and of B. McAlpin, B. Virden, and H. Kamemoto, who provided critical living material. Descriptions are largely based on living collections, but descriptive data were supplemented by the extensive collections at MO and borrowed collections from A, BR, CAS, CR, F, G, H, K, M, MEXU, MICH, NY, P, UC, and US. I thank the curators of these herbaria for the loan of materials. Finally, I acknowledge the technical assistance of Frances Mazanec, Patricia Croat, Ann Ruger, and Emily Colletti. 2 Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166. ANN. MISSOURI BOT. GARD. 70: 211-420. 1983. This content downloaded from 192.104. 39.2 on Sat, 09 May 2015 01:34:21 UTC All use subject to JSTOR Terms and Conditions 212 ANNALS OF THE MISSOURI BOTANICAL GARDEN [VOL. 70 2,500 species. It is worldwide in distribution but has most species in tropical areas. Its centers of distribution include both Asia and America (Croat, 1979). There are 14 genera restricted to Africa, and a few genera restricted to temperate regions of the northern hemisphere, including the Mediterranean region. Important local centers of diversity include subtropical and warm temperate South America, with eleven endemic genera, and the Indomalayan region, with thirteen endemic genera. At least 1,350 species, roughly 55 percent of the total, occur in the New World tropics and subtropics. Roughly half of these are Anthurium. MATERIALS AND ACKNOWLEDGMENTS The terminology and usage in the descriptions in this paper are defined in "Standardization of Anthurium Descriptions" (Croat & Bunting, 1979). Colors referenced in the descriptions that follow are taken from the color chart by Berlin and Kay (1969). This color chart, available from the University of California Press, is a reproduction of the Munsell Color Array of 40 hues, at maximum saturation, with nine degrees of brightness. The B & K (Berlin & Kay) color chart, as it is referred to here, represents 40 hues in the vertical columns and 9 degrees of brightness in the horizontal rows. Colors are arranged in 10 basic clusters with 4 different hues per cluster, ranging from red through yellow, green, blue, purple, and finally red-purple. The four columns for each color cluster are numbered 2.5, 5, 7.5, and 10. These numbers are repeated for each basic color type. The colors from the B & K color chart are read by first reporting the color, then the row followed by the column. For example, the third color in the fifth row in the red area would be called Red 5/7.5. The second color in the eighth row would be called Red 8/5. I have preceded the color references by B & K to indicate which color chart is being used. Although a more complete discussion of flowering behavior of Anthurium has been published elsewhere (Croat, 1980), mention should be made here of the descriptions of flowering behavior, especially with regard to the development of stigmatic droplets and the progressive development of stamens. Most observations reported here are based on the study of cultivated material, and references to the degree of accumulation of stigmatic fluid might be inaccurate in the absence of pollinators to remove it. Nevertheless, these observations show that important taxonomic characters are exhibited by the timing and amount of stigmatic fluid and particularly by the developmental sequence of the stamens. They are therefore recorded here as part of the description of the species where they have been observed. All estimates of ecological zones given in this paper are based on either Holdridge Life Zone maps for most Central American countries and for Panama or on the "Mapa de tipos de vegetacion de la Republica Mexicana" (Flores et al., 197 1). As yet no study has been made to correlate the vegetation types represented on the Mexican map with those of the Holdridge Life Zone system. For an understanding of this system see Holdridge, et al. ( 197 1). DISTRIBUTION OF ANTHURIUM Anthurium ranges from Mexico (Tamaulipas on the Caribbean slope and Nayarit on the Pacific slope) to northern Argentina and Paraguay. Species diversity is greatest in the low and middle elevations of northern South America, Panama, and Costa Rica, with less important centers in the mountains of southern Mexico and southeastern Brazil. While the upper Amazon forests of Bolivia and especially Peru, Ecuador, and Colombia are rich in species, the lower Amazon is relatively poor in species. DISTRIBUTION OF CENTRAL AMERICAN