Sedges: Cyperus to Scleria

Introduction

Introduction This volume is the first of two devoted to a group of plants known as sedges, belonging to the family Cyperaceae. This first part of the treatment of Illinois sedges contains the genera Cyperus, Dulichium, Eleocharis, Fimbristylis, Bulbostylis, Lipocarpha , Fuirena, Scirpus, Eriophorum, Rhynchospora, Cladium, and Scleria. The second volume is concerned only with the genus Carex. The plants in this family produce flowers, although the flowers are greatly reduced and do not possess any colorful petallike structures. To many amateurs, the sedges are often not distinguished from the similarly appearing grasses. Since sedges do produce flowers, they are classified as Angiosperms and, since only a single seed-leaf, or cotyledon, is formed upon germination, they are further designated as monocots. Other monocots are arrowheads, lilies, irises, orchids, rushes, etc., which are treated in other volumes in the Illustrated Flora series. (Flowering Plants of lllinois: Flowering Rush to Rushes [1970]; Flowering Plants of Illinois: Lilies to Orchids [197oa].) Grasses, likewise, are monocots, and have appeared in previous volumes in the series ( Mohlenbrock 1972, 1973). The nomenclature followed in this volume is based largely on the most recent monographic treatments available. Synonyms, with complete author citation, which have applied to species in the northeastern United States, are given under each species. A description, based primarily on Illinois material, is provided for each species. The description, while not intended to be complete , covers the important features of the species. Common names, other than "sedge," are generally not used for members of the Cyperaceae. Local names when they are used, however, are indicated. The habitat designation is not always the habitat throughout the range of the species, but only for it in Illinois. The overall range for each species is given from the northeastern to the northwestern extremities, south to the southwestern limit, then eastward to the southeastern limit. The range has been compiled from various sources, including examination of herbarium material. A general statement is given concerning the range of each species in Illinois. Dot maps show1 z I SEDGES ing county distribution of each sedge in Illinois are provided. Each dot represents a voucher specimen deposited in some herbarium. There has been no attempt to locate each dot with reference to the actual locality within each county. The distribution in Illinois has been compiled from field study as well as herbarium study. Herbaria from which specimens have been studied are Eastern Illinois University, Field Museum of Natural History, the Gray Herbarium of Harvard University, Illinois Natural History Survey, Illinois State Museum , Missouri Botanical Garden, New York Botanical Garden, Southern Illinois University, the United States National Herbarium , the University of Illinois, and Western Illinois University . In addition, a few private collections have been examined. To the curators of these herbaria, extreme gratefulness is accorded for their courtesies. Each species is illustrated, showing the habit as well as some of the distinguishing features in detail. Mrs. Fredda Burton has prepared the illustrations. There are several persons to whom the author is indebted for assistance in this study. Mr. Floyd Swink of the Morton Arboretum , Lisle, Illinois, has read and commented on the entire manuscript . Dr. Donald J. Drapalik assisted in preparation of the text of Eleocharis. Special thanks must go to the herbarium and library staff of the Missouri Botanical Garden. The Graduate School of Southern Illinois University furnished funds for some of the field work and for the illustrator. Dr. Dan. K. Evans has aided me immeasurably in this work. MORPHOLOGY OF ILLINOIS SEDGES The term sedges refers to those plants assigned to the family Cyperaceae. These are plants which have grasslike leaves and clustered flowers devoid of a perianth. Each flower is subtended, instead, by usually a single scale. The chief technical difference between sedges and grasses is in the fruit which, in the grasses, has the seed adjoined to the pericarp, or ovary wall, while in the sedges, the seed is not fused with the pericarp. Other differences, primarily concerning vegetative characters, include such things as a generally hollow stem in grasses, solid in sedges, open sheaths in grasses, closed in sedges, 2-ranked leaves in grasses, 3-ranked in sedges, and anthers versatile in grasses, basifixed in sedges. Introduction I 3 Sedges are annuals or perennials. The annuals possess tufts of fibrous roots (Fig. 1) and live for a single growing season. Perennials may be tufted, but they usually have rhizomes (Fig. 2), or they may have...