Dissertation Research: Systematics and Phylogeny in Carex sect. Griseae (Cyperaceae)

莎草是多年生草本植物，类似于草，叶长而窄，花小而单性，主要由风媒授粉。莎草在世界各地都有分布，但在北美和东亚最为多样化。它们生长在广泛的栖息地，许多物种仅限于特定的当地环境。莎草在湿地演替、泥炭发育和斜坡稳定中发挥着重要作用，它们为野生动物提供食物和庇护所。尽管它们具有重要的生态意义，但它们的分类学状况很差，大量物种的描述仅基于少数几个通常不可靠的形态特征。研究生罗伯特·纳齐在密歇根大学教师赞助人安东·雷兹尼克的指导下，正在研究苔草属苔草组莎草的分类和进化。苔草组苔草属约有17个物种，原产于北美东部。来自形态、解剖学和染色体研究的数据将被用来划定一致的物种，并将根据土壤底物和地理范围绘制地图。将与其他莎草组进行比较，以假设该组可能的系统发育，以便将来用分子数据进行测试。该项目的结果应该是对全世界对莎草的生物学和进化感兴趣的系统学家和生态学家有用的模型调查。

Sedges are perennial herbs that resemble grasses, with long, narrow leaves and small, unisexual flowers that are mostly wind pollinated. Sedges have a worldwide distribution but are most diverse in North America and eastern Asia. They grow in a wide range of habitats, and many species are restricted to particular local environments. Sedges play important roles in wetland succession, peat development, and stabilization of slopes, and they provide food and shelter to wildlife. Despite their ecological importance, their taxonomy is in poor condition, with large numbers of species described on the basis of only a few, often unreliable morphological features. Graduate student Robert Naczi under the guidance of faculty sponsor Anton Reznicek at the University of Michigan is studying the taxonomy and evolution of sedges of the genus Carex section Griseae, a group of about 17 species native to eastern North America. Data from the study of morphology, anatomy, and chromosomes will be used to delimit coherent species, and these will be mapped against soil substrate and geographical range. Comparisons with other sedge groups will be made to hypothesize a likely phylogeny for the group, for future testing with molecular data. The results of the project should be a model investigation useful to systematists and ecologists worldwide who are interested in the biology and evolution of sedges.