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Free-floating is the term used for plants which float at or beneath the water surface without attachment to the substrate. Free-floating aquatics are transported freely by wind and currents, so they are normally found in abundance only in calm, sheltered waters. Duckweed (Lemna spp.), bladderwort (Utricularia vulgaris), and coontail (Ceratophyllum demersum) are common examples of free-floating aquatics.2. Submergent describes plants anchored to the bottom by roots or rhizomes. Their foliage is either entirely submersed or some floating leaves may also be present. Reproductive structures may be submersed, floating, or borne above the water surface. Submergent plants occur in very shallow to deep water, depending upon water clarity, substrate, and growth form. Some common examples include pondweed (Potamogeton spp.), water milfoil (Myriophyllum spp.), waterweed (Elodea spp.), and widgeongrass (R uppia m aritima) .3. Emergent refers to those species which occur on saturated soils or on soils covered with water for most of the growing season. The foliage of emergent aquatics is partly or entirely borne above the water surface. Examples of emergent aquatics are many, including arrowhead (Sagittaria spp.), cattail (Typha spp.), common reed (Phragmites australis), and bulrush (Scirpus spp.).4. Amphibious applies to aquatic species which are capable of growing as either submergent or emergent aquatics. These species commonly assume a semi-terrestrial growth form when stranded by a receding water level. The semi-terrestrial growth form usually differs markedly in appearance from the submersed growth form. Amphibious aquatics include yellow water-crowfoot (Ranunculusflabellaris, R. gmelinii), pepperwort (Marsilea vestita), and water smartweed (Polygonum amphibium).Many of the species included by this treatment fit none of the categories given above. These are plants that ordinarily inhabit wet meadows, shores, streambanks, exposed mud flats, and other marginal habitats where the soil is saturated for only part of the growing season. Since these habitats are inherent to prairie wetland ecosystems, the plants which inhabit them are logically part of the wetland flora. They are, therefore, admitted to this treatment as wetland plants.Not all wetland plants are restricted to wetland habitats. A considerable number of them are also found in upland situations. Many are opportunistic weedy species that rapidly invade soil left bare by receding water. Plants like barnyardgrass (Echinochloa muricata), foxtail barley (Hordeum jubatum), and common plantain (Plantago major) are KEY TO TAXA OF AQUATIC AND WETLAND VASCULAR PLANTS1 Plants small and flattened, less than 3 cm across, free-floating at or beneath the water surface, often not differentiated into stems and leaves; fine roots often produced on the underside of the plants.2 Plants with tiny, overlapping, scalelike leaves in 2 rows on branched, filiform

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Highlight: To help resolve conflicting claims about the severity of predator losses to the sheep industry, sheep losses from all causes were assessed during 1973-75 in five southern Wyoming ranches. Although herd sizes varied seasonally and yearly, about 6,000 ewes and their lambs were monitored each year during spring lambing and the summer and winter grazing seasons. Most of the sheep were tended by herders. Lamb bss was greater than ewe, and spring losses were always greater than summer and winter losses combined. Of 4,440 dead sheep examined, predators killed 1,030 or 23%. Although predation was the largest single cause of death for lambs (24%), weather-related losses such as deaths from exposure, starvation, accidents or disease, if combined, would probably have been higher. Disease killed the most ewes (260/o), with predation the second most important cause of death (18%). Of the deaths from predation, coyotes caused 77%, black bears ll%, and golden eagles 9%. During the 3 years, known predator kills were 0.2% of the ewes each year and l.S%, 2.1%, and 3.2%, respectively, of the lambs from the study herds. There were 1,235 ewes and iambs missing, mostly after the summer season, mainly due to miscounting and loose management-from one ranch.

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