The Araceae are exceptionally diverse by nearly all phenetic criteria. The two most widely accepted infrafamilial classification systems, those of Engler and Hutchinson, emphasize vegetative and floral morphology, respectively, and are thus rather dissimilar. A more balanced scheme, in which all available phenetic data are considered, is attempted here. Character state polarities are inferred, and synapomorphies utilized to circumscribe infrafamilial taxa. Among the character states considered primitive for Araceae are: a rhizomatous or caulescent growth habit; simple, cordate leaf blades; parallel venation; a simple, green spathe; bisexual, perigoniate flowers; trilocular ovaries with axile placentation; anatropous, crassinucellate ovules; elongate stamens with longitudinal anther dehiscence; a base chromosome number of x = 7 or 14; and monosulcate, reticulate, binucleate pollen grains lacking starch. These and other conclusions have been employed in a character analysis of araceous subtaxa accepted a priori as natural. Significant features of the classification derived from a cladogram reflecting this analysis include: the merger of Engler's subfamilies Pothoideae and Monsteroideae, and the dissolution of his Calloideae; a drastic internal rearrangement of the Colocasioideae; and the recharacterization of the Aroideae, involving the transfer of several tribes to the Philodendroideae and the assimilation of the subfamily Pistioideae (Pistia stratiotes L.) and the tribe Thomsonieae (formerly included in subfamily Lasioideae). The following suprageneric nomenclatural novelties are created: Cercestideae Grayum, trib. nov.; Protarinae (Engl.) Grayum, stat. nov.; Remusatiinae Grayum, subtrib. nov.; Jasarinae Grayum, subtrib. nov.; and Scaphispathinae Grayum, subtrib. nov.
In 1914, the Annals of the Missouri Botanical Garden, the flagship journal of the scientific publications program, was founded to contain research contributions from staff members at the Garden, graduate students of the Henry Shaw School of Botany of Washington University, and from visiting botanists associated with the Garden. Since that time, the Annals has grown to be one of the world's premiere peer-reviewed botanical journals, published quarterly, with an emphasis on systematic botany and taxonomy. Articles are accepted in English and Spanish, from botanists at the Garden and from the international botanical community.
The Missouri Botanical Garden was founded in 1859 by the successful English businessman Henry Shaw and is the oldest botanical garden in the United States. Within its 79 acres are spectacular display and demonstration gardens and rare collections of botanical, horticultural, and historical materials, as well as architecturally and historically significant buildings. Today the Garden is a major cultural institution, a designated National Historical Landmark, and a world-renowned botanical research center. The Missouri Botanical Garden Press, an integral part of the Garden's research division, has a history of over 100 years of scientific publications. Since the publication of the Trelease article in 1890, the program has grown phenomenally. It includes two quarterly scientific journals, a series of books on various aspects of botanical research, and several floras that cover botanically significant areas of the world. The Annals of the Missouri Botanical Garden, the Garden's primary scientific journal, was founded in 1914 and concentrates on systematic botany and taxonomy. The Annals is known for its traditional monographs and revisions of plant genera, as well as cutting-edge articles on molecular phylogenetics, and for its themed issues, on topics such as the origin of modern terrestrial ecosystems and recent discoveries in the plant, animal, and other kingdoms. Novon, a journal for botanical nomenclature, began in 1991 and contains papers establishing new nomenclature in vascular plants and bryophytes. The number of pages continues to grow from year to year, an indicator of the important niche in the botanical systematics community filled by this journal. Monographs in Systematic Botany from the Missouri Botanical Garden were started in 1978 as a way of making lengthy botanical works available as well-made, stand-alone volumes. The series includes several single-topic treatises, as well as ongoing titles, such as the Moss Flora of Central America, Icones Pleurothallidinarum, Index to Plant Chromosome Numbers, and many more. MBG Press is also the proud publisher of several regional and national floras, including those of China, Mesoamerica, Nicaragua, the Venezuelan Guayana, Panama, and more. For a full listing, and for more information on Research at the Missouri Botanical Garden, see www.mobot.org.