A New Combination for a Brazilian Aroid

Publication Type:Journal Article
Year of Publication:2012
Authors:Goncalves, E. G., Santos, A. Henrique d, Miller P. Richard Mo
Journal:Aroideana; Journal of the International Aroid Society
Start Page:35
Keywords:Caladieae, Caladium, Mangaritoroxo, Xanthosoma

The species originally described as Caladium poecile Schott (Araceae) is here proposed as belonging to the genus Xanthosoma, as X. poecile (Schott) E.G. Gonç.. This new combination is based on pollen grains (shed in tetrads), together with molecular results. This is the third species of Xanthosoma known to have peltate leaves.

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In 1832 Heinrich Wilhelm Schott cited Caladium poecile for the first time in his Meletemata Botanica. However, no description was presented nor was any specimen cited. The first description for this name was prepared in Schott’s Synopsis Aroidearum (1856) which can be considered the first effective publication, but once again no specimen was cited. Furthermore Schott (1860) cited that he had seen living specimens both spontaneous and cultivated. Unfortunately, the only material that survived was the plates in Schott’s Icones Aroideae (3570–3575) and the color plate presented in Peyritch’s Aroideae Maximlianae (1879).
In 2007, the junior author (AHS) contacted the senior author (EGG) asking for identification of an aroid cultivated by German settlers in Southern Brazil. Together with dry specimens, a few corms were also sent to be cultivated at Universidade Católica de Brası ´lia. At a first glance, it looked like an unusual Caladium, because of purplish petiole, the peltate leaves usually with a red adaxial spot in the opposite face of the petiole attachment. In a few months some of the corms flowered and the inflorescences could be analyzed. The observed pollen grains were surprisingly shed in tetrads (that would suffice to exclude this species from Caladium, based on Madison, 1981) and the gynoecium also resembled Xanthosoma, mainly because of the discoid style. Furthermore, molecular analysis based on chloroplast markers (to be published elsewhere) confirmed its position within Xanthosoma. Since this material from Santa Catarina state matched the plates of Caladium poecile, a combination as presented here was needed.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith