Two new species (Gustavia johnclarkii and G. hubbardiorum) and other contributions to the systematics of Gustavia (Lecythidaceae) 1 2 SCOTT A. MORI AND XAVIER CORNEJO 1 Institute of Systematic Botany, The New York Botanical Garden, 200th St. and Kazimiroff Boulevard, Bronx, NY 10458-5126, USA; e-mail: [email protected] 2 Herbarium GUAY, University of Guayaquil, P.O.Box 09-01-10634, Guayaquil, Ecuador; e-mail: [email protected] Abstract. Gustavia johnclarkii and G. hubbardiorum, two new species from the wet forests of northwestern and Amazonian Ecuador, are described and illustrated. In addition, the two subspecies of both G. speciosa and G. macarenensis are elevated to species, and the new combination Gustavia paucisperma is provided. A justification for these changes is presented. Key Words: Ecuador, Gustavia johnclarkii, Gustavia hubbardiorum, Lecythidaceae, Neotropics. Resumen. Gustavia johnclarkii y G. hubbardiorum, dos nuevas especies de los bosques muy húmedos del noroeste y de la Amazonía ecuatoriana, son descritas e ilustradas. Además, las dos subespecies de G. speciosa and G. macarenensis son elevadas al rango de especies, y se presenta la nueva combinación Gustavia pauci- sperma. Se incluye la justificación para el reconocimiento de estas nuevas especies. The last monograph of the neotropical Gus- again by examining the original specimens. On tavia was published by Mori (1979), and no the other hand, if two taxa are subsequently species have been described or additions to the lumped together the separate descriptions can be knowledge of the systematics of this genus have manually joined together to produce a descrip- been published since then. During that 33 year tion of the more broadly defined species. period, many new collections have been gath- The use of databases to generate new taxon ered, and the senior author’s philosophy about concepts makes the process of lumping and species concepts has changed with regard to splitting even easier. When the original species splitting and lumping. Early in his career, Mori description is driven by characters derived from looked for similarity among populations and, a specimen database in which the characters thus, recognized a number of infraspecific taxa. derived from each specimen are documented, Todayhebelievesthatitismoreusefulto segregated taxon descriptions can be generated describe entities that can be recognized by electronically by changing the determinations for others (based on a suite of characters) as the collections representing each of the newly separate species. His rationale for this philoso- joined or separated taxa (Mori et al., 2011). phy is that it is easier to add separate descrip- Unfortunately, the classification of tropical tions together than it is to tease apart a trees is much more complicated than lumpers description that encompasses two or more taxa. versus splitters. These philosophical differences When what was initially recognized as a single are difficult to reconcile because it is often a species is subsequently separated into two matter of opinion regarding exactly how differ- distinct species, the descriptions for each of the ent plant populations need to be to merit segregated species often have to be written recognition as distinct species. This oversimpli- Brittonia, DOI 10.1007/s12228-012-9282-9 ISSN: 0007-196X (print) ISSN: 1938-436X (electronic) © 2013, by The New York Botanical Garden Press, Bronx, NY 10458-5126 U.S.A. BRITTONIA [VOL XX fies the situation because species delimitations ical features are also likely to arise with the are defined by a much wider range and use of molecular data (particularly when the complexity of species concepts than those of molecular data are collected from a small simply lumpers and splitters (Luckow, 1995). sample of plants). Because the genome of a The circumscription of species of neotrop- species influences its morphological charac- ical Lecythidaceae is especially difficult be- teristics, variation of the former correlates cause of the following: 1) The long life cycle with variation of the latter and, thus, the of trees makes it unlikely that data from greater the morphological variation the great- crosses of individuals from different popula- er the genetic variation. Thus, as more and tions would be available during the lifetime more populations are sampled, genetic differ- of those trying to define taxon limits; 2) ences that were originally thought to distin- Trees, especially those found in and above guish species will often turn out to be part of the canopy, are physically difficult to collect; a gradient or network. Regardless of the data 3) Collections of all stages of a tree’s life source, almost all species descriptions are cycle, let alone from the same trees, are based on a small subset of what is essentially seldom collected; 4) Collections often do not an infinite number of individuals making up capture all of the information that could be plant populations; therefore, further sampling used to separate species; 5) Variation within will reveal more morphological and molecu- trees, e.g., the differences among leaves from lar variation that may have been described in different parts of the canopy (Kincaid et al., the original species concepts. 1998), are poorly known; 6) How morpho- In addition to morphological differences, logical variation relates to the different closely related species are often found in environments in which species occur is different geographic areas and prefer different seldom studied; 7) Among population varia- habitats, and sometimes flower and fruit at tion is poorly understood; and 8) Conclusions different times of the year. For example, the are made based on data from a finite number segregation of the two subspecies of Gustavia of individuals gathered from a species with an macarenensis proposed in this paper is infinite number of individuals. One of the supported by the wide geographic separation main reasons that new collections sometimes of their ranges; differences between Amazo- do not correspond to current circumscriptions nian species of Allantoma are sometimes and identification keys of taxa is that they reflected in their habitat preferences (e.g., A. reveal variation that has not yet been lineata [Mart. ex O. Berg] Miers grows in recorded. wet areas and A. decandra [Ducke] S. A. In the very early stages of neotropical plant Mori, Y.-Y. Huang & Prance grows in terra exploration (e.g., Aublet, 1775), nearly all firme forest (Ducke, 1948); and two sympat- collections represented “new species.” How- ric species of Corythophora in central Ama- ever, as exploration intensified, new collec- zonia have different flowering and fruiting tions were gathered and morphological times (e.g., C. alta R. Knuth flowers and intermediates were found linking populations fruits earlier in the year than C. rimosa W. A. that were previously thought to represent Rodrigues subsp. rimosa [Prance & Mori, separate species—thereby causing the need 1979]). These differences, however, are only to place some names in synonymy under the revealed after extensive field study of the first name given to the species as dictated by species. the International Code of Botanical Nomen- Although great strides have been made to clature (McNeill et al., 2006). Some research- enhance the quality and reproducibility of ers assume that molecular data will help botanical data and plant classification, sys- resolve problems with species limits, and tematic botany is not an exact science while that will undoubtedly be the case for (Burger, 2006). Therefore different botanists some taxa, molecular data is not a panacea will most likely continue to have different that will resolve all difficulties with plant interpretations of species limits no matter classification. The same problems that arise how complete the sampling or how sophisti- when defining species based on morpholog- cated the techniques used to distinguish 2013] MORI & CORNEJO: GUSTAVIA (LECYTHIDACEAE) species become. The changes in plant no- cotyledons. In addition, the fruits of Gustavia menclature that accompany a better under- are indehiscent and globose in shape and the standing of their evolutionary relationships seeds are of two major types: those with are a considerable source of frustration for relatively thick seed coats and funicles sur- non-specialists, but users of taxonomic data rounded by a thick, yellow, contorted aril must understand that botanists are striving to (e.g., G. augusta), and those with fragile seed achieve a stable classification that indicates coats and inconspicuous funicles surrounded evolutionary relationships. by a tubular aril (e.g., G. nana Pittier and G. Gustavia forms a clade that is always superba). recovered in both morphological (Mori in Gustavia, now with 46 species, is second Prance & Mori, 1979) and molecular studies only to Eschweilera in number of species. (Mori et al., 2007). Morphologically, this One difficulty in circumscribing species is clade is distinguished by the following that at first glance most of the flowers look features. The growth form of species of the same to such an extent that there are Gustavia is more variable than any other few species that can be easily distinguished species of neotropical Lecythidaceae—some by looking at apical or lateral views of species are pachycauls with very robust stems flowers. Upon closer examination, differ- (greater than 10 mm diam.) that can be ences in the following characters become unbranched (e.g., G. monocaulous S. A. apparent: the position of the