Taxonomic Revision of Dieffenbachia of Mexico and Central America

9306891 Croat对热带地区丰富的植物进行鉴定和分类的最有效方法仍然是实地采集原生生境的植物，然后进行深入的实验室和植物标本室研究。密苏里植物园（Missouri Botanical Garden）的托马斯·克罗特（Thomas Croat）博士是一名花楸科的专家，他正在研究墨西哥和中美洲的新热带花楸属（Dieffenbachia），估计有30-35个物种，正在为该属的分类学专著做准备。就美国的商业销售而言，该属包括观赏植物的第二重要物种；然而，物种之间的关系，育种种质来源，地理范围，传粉和传播生物学以及可能的杂交方面知之甚少。从活体材料和植物标本馆标本中提取的植物描述信息被输入计算机数据库，最终将通过互联网提供给感兴趣的研究人员和学生。这项研究将有助于改进对每个物种的诊断，初步说明系统发育关系，绘制地理范围，记录开花和结果的物候学和生态学的其他方面，以及确定可靠的学名的关键。热带地区植物多样性的清查工作仍由一小组热心的分类学专家进行。他们收集的标本，包括植物标本馆的标本和植物园里的活的材料，以及出版的信息和现在的计算机化记录，成为明智使用和管理的资源。

9306891 Croat Field collecting of plants in native habitats followed by intensive laboratory and herbarium study remain the most efficient means of identifying and classifying the rich plant life of the tropics. Dr. Thomas Croat of the Missouri Botanical Garden, a specialist on the aroid or philodendron family, is studying the neotropical genus Dieffenbachia in Mexico and Central America, with an estimated 30-35 species, in preparation for a taxonomic monograph of the group. The genus includes the second most important species of ornamental plant in terms of commercial sales in the U.S.; however, relationships among species, sources of germplasm for breeding, geographical ranges, and aspects of pollination and dispersal biology and possible hybridization are poorly known. Descriptive information about the plants, taken from living material and herbarium specimens, is entered in a computer database, which eventually will be accessible over the Internet to interested researchers and students. The research will lead to improved diagnosis of each species, a preliminary account of phylogenetic relationships, mapping of geographic ranges, notes on flowering and fruiting phenology and other aspects of ecology, and identification keys for reliable assignment of scientific names. The inventory of plant diversity in the tropics remains an ongoing endeavor by a small group of devoted taxonomic specialists. The collections they create, both herbarium specimens and living material in botanical gardens, and the published information and, now, computerized records, become resources for wise use and stewardship.