Volume 101 Annals Number 1 of the 2015 Missouri Botanical Garden A REVISION OF THE GENUS Thomas B. Croat3 and Lynn P. Hannon CHLOROSPATHA (ARACEAE)1,2 ABSTRACT This is the first revision of the genus Chlorospatha Engl. (Araceae) since Michael Madison’s 1981 treatment. The genus consists of three sections, two of which are newly established: Chlorospatha sect. Occidentales Croat & L. P. Hannon and Chlorospatha sect. Orientales Croat & L. P. Hannon. Included are 69 taxa (68 species and one variety) for Central and South America, of which 45 are new to science. These include 39 newly described species: C. bayae Croat & L. P. Hannon, C. boosii Croat & L. P. Hannon, C. bullata Croat & L. P. Hannon, C. caldasensis Croat & L. P. Hannon, C. caliensis Croat & L. P. Hannon, C. carchiensis Croat & L. P. Hannon, C. cedralensis Croat & L. P. Hannon, C. chocoensis Croat & L. P. Hannon, C. congensis Croat & L. P. Hannon, C. engleri Croat & L. P. Hannon, C. giraldoi Croat & L. P. Hannon, C. grayumii Croat & L. P. Hannon, C. hannoniae Croat, C. hastata Croat & L. P. Hannon, C. huilensis Croat & L. P. Hannon, C. jaramilloi Croat & L. P. Hannon, C. limonensis Croat & L. P. Hannon, C. litensis Croat & L. P. Hannon, C. longiloba Croat & L. P. Hannon, C. maculata Croat & L. P. Hannon, C. mansellii Croat & L. P. Hannon, C. morae Croat & L. P. Hannon, C. munchiquensis Croat & L. P. Hannon, C. nambiensis Croat & L. P. Hannon, C. narinoensis Croat & L. P. Hannon, C. noramurphyae Croat & L. P. Hannon, C. oblongifolia Croat & L. P. Hannon, C. portillae Croat & L. P. Hannon, C. pubescens Croat & L. P. Hannon, C. queremalensis Croat & L. P. Hannon, C. risaraldensis Croat & L. P. Hannon, C. sagittata Croat & L. P. Hannon, C. sizemoreae Croat & L. P. Hannon, C. stellasarreae Croat & L. P. Hannon, C. sucumbensis Croat & L. P. Hannon, C. timbiquensis Croat & L. P. Hannon, C. tokioensis Croat & L. P. Hannon, C. yatacuensis Croat & L. P. Hannon, and C. yaupiensis Croat & L. P. Hannon. Four additional and putative new species are described in detail at the end of the taxonomic treatment and are included in the key, but not formally named; they are labeled Species 1 to 4 and are assumed to be new. They were collected as sterile plants and will be formally described only after recollection in fertile condition. Two combinations are made: C. plowmanii (Madison) Croat & L. P. Hannon and C. croatiana Grayum var. enneaphylla (Grayum) Croat & L. P. Hannon. Species diversity of Chlorospatha is greatest in the Andes of Colombia and the western Andes of northernmost Ecuador, and diminishes from northernmost Colombia into Central America and from central Ecuador southward to the border with Peru. Costa Rica has two taxa (one species, one variety), Panama four taxa (three species, one variety), Colombia 45 taxa (44 species, one variety), and Ecuador 24 species. Endemism is 1 The authors wish to thank the curators of those institutions listed above, from which we borrowed the material used in our study, but especially Richard Wunderlin and Bruce Hansen from the University of South Florida (USF), who allowed the study of this material in their herbarium. Special thanks also go to Roy Gereau (MO) for his translations from original Latin descriptions; to Richard Keating for his contribution of the Anatomy of Vegetative Structures; to Michael Hesse and Heidi Halbritter for contributing micrographs of pollen; to Eduardo Goncalves¸ (Brasilia) for his contribution of information regarding Xanthosoma; to Michael Grayum (MO) for clarifying the concepts of shoot growth in Chlorospatha and providing a terminology for the various structures associated with flowering; and to Josef Bogner (M) for his translation of Engler’s German text and reviewing the manuscript, also to Simon Mayo (K) for his manuscript review. We owe special thanks to the editors of Willdenowia for permission to use data from their journal; Elizabeth Coachman for her illustrations of the various types of styles that occur in Chlorospatha; Brigham Fisher (MO) for scanning of herbarium specimens for figures; and Emily Yates (MO) for figure plate layout and Carla V. Kostelac (MO) for general manuscript editing. 2 This manuscript is dedicated to Lynn P. Hannon who was born on July 8, 1948, and died on July 10, 2006. Lynn’s strong interest and dedication to the genus Chlorospatha led to this revison. Lynn spent many hours in the field with the senior author who encouraged her to write this compilation of the plants with which she became so familiar. 3 Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A. [email protected] doi: 10.3417/2005079 ANN.MISSOURI BOT.GARD. 101: 1–259. PUBLISHED ON 9SEPTEMBER 2015. 2 Annals of the Missouri Botanical Garden highest in Colombia, with 43 species currently considered endemic, followed by Ecuador with 23 endemic species, and Central America with two endemic species. Key words: Araceae, Central and South Americas, Chlorospatha. Chlorospatha Engl. is, after Xanthosoma Schott, Chlorospatha sect. Orientales Croat & L. P. Hannon the largest genus in the tribe Caladieae Schott, in is comprised of 10 species known only from the subfamily Aroideae (Mayo et al., 1997, 1998), family eastern slopes of the Andes in Ecuador. Araceae, with 68 species involving 69 taxa (see Appendix 1). Numerous collections of what are MATERIALS AND METHODS presumably new taxa of Xanthosoma were examined This revision is based on approximately 46 during the current investigation, which would combined years (37 for the senior author and nine eventually bring the total number of Xanthosoma for the junior author) of field studies in Central and well above the current total of 66 species (Govaerts & South America, between 1967 and 2004. All but 28 Frodin, 2002). This is the first complete revision of of the 72 taxa were studied in the field and/or in Chlorospatha since that of Engler and Krause (1920), cultivation. Those known only from herbarium although Michael Madison’s generic treatment in material are: Chlorospatha amalfiensis Croat & L. Selbyana (1981) served to update the genus and was P. Hannon, C. antioquiensis Croat & L. P. Hannon, C. very useful for our work. Chlorospatha occurs from betancurii Croat & L. P. Hannon, C. caldasensis Croat approximately 108200N latitude to 48160S latitude & L. P. Hannon, C. caliensis Croat & L. P. Hannon, and inhabits a wide range of mesic habitats from near C. callejasii Croat & L. P. Hannon, C. carchiensis sea level to 3000 m elevation, in life zones Croat & L. P. Hannon, C. cedralensis Croat & L. P. (Holdridge, 1967) ranging from tropical moist forest Hannon, C. cogolloi Croat & L. P. Hannon, C. to montane rainforest, with premontane wet forest the congensis Croat & L. P. Hannon, C. corrugata Bogner predominant ecological zone. The genus is known &Madison,C. cutucuensis Madison, C. gentryi from dark forest understory, frequently in wet to Grayum, C. hastifolia Bogner & L. P. Hannon, C. boggy areas, in wet ravines and in association with jaramilloi Croat & L. P. Hannon, C. kressii Grayum, small streams, but because of its usually small to C. lehmannii (Engl.) Madison, C. luteynii Croat & L. moderate size, it is often inconspicuous. Numerous P. Hannon, C. macphersonii Croat & L. P. Hannon, C. species are quite attractive, but have proved to be nambiensis Croat & L. P. Hannon, C. nicolsonii Croat short-lived and demanding in cultivation, possibly & L. P. Hannon, C. noramurphyae Croat & L. P. owing to specialized habitat requirements. During the Hannon, C. risaraldensis Croat & L. P. Hannon, C. course of fieldwork in Colombia and Ecuador, we stellasarreae Croat & L. P. Hannon, C. sucumbensis observed that different species did not occur together Croat & L. P. Hannon, C. timbiquensis Croat & L. P. or in close proximity, although they occurred in the Hannon, C. yatacuensis Croat & L. P. Hannon, and C. same general areas. Species were found only as yaupiensis Croat & L. P. Hannon. One species was solitary or few individual plants and occasionally in published by Croat and Bogner as Xanthosoma small colonies, but rarely in abundance at any given feuersteiniae Croat & Bogner (Croat & Bogner, site. This would suggest the possibility that micro- 2005) and later transferred to Chlorospatha by climates, pollination strategies, or other requirements Bogner and L. P. Hannon (Bogner & Hannon, are responsible for segregation of species. Not all 2007). Finally, C. hastifolia was published in 2007 species were observed in the field; therefore, it could (Bogner & Hannon, 2007). Except for these, all not be said with certainty that this segregation of descriptions have been prepared from both living and species is typical of the genus without further study dried specimens. The use of ‘‘dried’’ preceding all or throughout the range of the genus. any part of the description is an indication that all Most species are members of Chlorospatha sect. that follows is based on herbarium material only. Occidentales Croat & L. P. Hannon (see Infrageneric Many of the cultivated plants were based upon the Relationships), comprised of 40 species from Colom- living collections of Lynn Hannon from Odessa, bia and Ecuador, only two of which occur on the Florida, and were disbanded upon her death. eastern slopes of the Andes. Chlorospatha sect. Terminology and usage in descriptions in this Chlorospatha is comprised of 18 taxa, most of which revision are largely defined by Croat and Bunting are from Colombia, but includes the three taxa from (1979). Further definitions of petiole cross-sectional Central America and one species from Ecuador. shapes are defined and illustrated in Croat (1983). Volume 101, Number 1 Croat & Hannon 3 2015 Revision of Chlorospatha (Araceae) Ecological zones, although occasionally estimated C. castula Madison, bringing the total number of from the first author’s experience with Central and Caladiopsis species to four.