Iowa's Non-Native Graminoids

Journal of the Iowa Academy of Science: JIAS

Volume 108 Number Article 8

12-2001

Iowa's Non-native Graminoids

Thomas R. Rosburg Drake University

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Recommended Citation Rosburg, Thomas R. (2001) "Iowa's Non-native Graminoids," Journal of the Iowa Academy of Science: JIAS, 108(4), 142-153. Available at: https://scholarworks.uni.edu/jias/vol108/iss4/8

This Research is brought to you for free and open access by the Iowa Academy of Science at UNI ScholarWorks. It has been accepted for inclusion in Journal of the Iowa Academy of Science: JIAS by an authorized editor of UNI ScholarWorks. For more information, please contact [email protected]. Jour. Iowa Acad. Sci. 108(4):142-153, 2001

Iowa's Non-native Graminoids

THOMAS R. ROSBURG

Department of Biology, Drake University, Des Moines, Iowa 50311

Iowa's non-narive graminoids include 60 species of grasses and one species of bulrush. The exoric grass species comprise a large proporrion (abour 31 % ) of rhe toral species richness of grasses in Iowa, which are second only ro rhe Asreraceae in rerms of toral species. About half of the non-native graminoids (52%) occur sporadically and form sparse, non-invasive populations, while eighteen species (about 30%) are commonly encountered in large populations throughour the state. About 60% are annuals and a large ma1onry (89%) has been introduced from either Europe or Asia. The C3 photosynthetic pathway is prevalent, occurring in approximately two thirds of the species. Grass species introduced for use as forage or grain account for over 40% of these non-native species. Among the nine species that are most ubiquitous throughout the state, six are forage or grain species. Although considered problematic in narural communities, many of these species provide valuable grassland habirar in some areas of rhe state. Biological data concerning growth, life history traits, and habirar affinities are provided for many of the most common species. A review of the literarure relared to the control of non-native grasses is also presented. In general, herbicides showed the greatest probabiliry of reducing the occurrence of non-narive grasses (effective 65% of rhe rime), prescribed fire worked 47% of rhe rime, and mowing was least effective, reporredly working 27% of rhe time.

INDEX DESCRIPTORS: herbicide, mowing, prescribed fire, exotic grass, invasive, Brornus, Poa, Festuca, Phalaris, Agropyron. Setaria, Digitaria, Echinochloa, Agrostis, Phleum.

Graminoids (or grass-like plants) are arbitrarily defined to include tend to form mats from growth by stolons. Among the 41 % of the three families-the grasses (Poaceae); the sedges (Cyperaceae), which exotic graminoids that are perennials, nearly half are caespitose also includes bulrushes, spikerushes, and nut sedges; and the rushes (forming dense, multi-tiller clumps and therefore somewhat less in Ouncaceae). Grasses represent nearly all of the state's introduced gra vasive), while about 36% are rhizomatous (forming loose spreading minoids, accounting for 60 species (Eilers and Roosa 1994). Those colonies and consequently more capable of colonization and expan 60 exotic grass species also comprise nearly one-third of the grass sion through vegetative growth). diversity in Iowa (about 194 species, Lynn Clark, Iowa State Uni Europe and Asia are the principal origin for most of these species, versity, personal communication). This contrasts sharply with the accounting for 87% of the relative frequency of origin. Over half of sedge family in which there is only one non-native species known the grasses were introduced for agronomic reasons, specifically to among a total of 163. The exotic sedge is a bulrush species collected produce either forage or grain. Use of the species in lawns and for in one county in southwestern Iowa (Eilers and Roosa 1994). There erosion control is the third and fourth most frequent reason for in are no introduced rushes among the 17 species known to occur in troduction. There is a large group of species without any apparent Iowa. Therefore, this review is essentially an examination of Iowa's reason for introduction; these probably represent accidental species. exotic grass species. As a whole, and unlike most other taxonomic groups, about two The checklist of Eilers and Roosa (1994) lists reed canary grass thirds of the exotic graminoids have been purposefully grown and (Phalaris arundinacea) as native. However, there is appreciable evi propagated in the state for agronomic purposes. They account for a dence that most populations are an introduced cultivar (Galatowitsch little over half (52%) of the relative abundance (based on the total et al. 1999), and so it will be treated as such in this paper. One of abundance indices for all species). Another 42% of the relative species of three-awn (Aristida rarnosissirna) listed by Eilers and Roosa abundance is represented by the accidental introductions. Together ( 1994) as a non-native species will be treated as native because it is these two categories, agronomic species and weedy species of agro indigenous to Missouri and the Iowa record occurs in the southeast nomic crops, account for nearly all (94%) of the relative abundance ern corner-a plausible record for a native species. By adding Phal indices. aris and dropping Aristida. the total of introduced graminoids re The majority of the exotic grasses are cool-season, or have the C 3 mains 61. Species nomenclarure follows Eilers and Roosa (1994). photosynthetic pathway. This reflects the primary purpose of their Slightly over 60% of these 61 exotic graminoids are annuals (Table introductions-to enhance forage yields by lengthening the growing 1), which indicates a ruderal strategy and a tendency to inhabit season of pastures and hayfields. It also means that many have a disturbed areas. These species are generally capable of exploiting competitive edge with native warm-season species because they begin disturbances in both time and space with life history characteristics regrowth from perennial roots earlier in the season. However, this such as high seed production, long distance dispersal, and high seed difference in phenology also provides an opportunity for selective longevity. Annuals lack vegetative growth, however, and are less control. Because plants are usually more susceptible to stress from competitive than perennials, which can be more invasive and difficult fire, mowing, or herbicides when they are physiologically active, to control. Most of rhe annuals are tufted (i.e., have multiple stems properly timed treatments will stress C3 grasses more than native or culms from branching at the base of the primary shoot). A few C4 species. · IOWA'S NON-NATIVE GRAMINOIDS 143

Tablel. Characteristics of Iowa's non-native graminoids. Com Table 2. Frequency ranges and scalar values used for calcu piled from descriptions in floras or papers that encompass the lating a species' abundance index from the four principal abun central United States, including Pohl 1966 and 1987, Correll dance categories used in Eilers and Roosa (1994). and Johnston 1970, Voss 1972, Swink and Wilhelm 1979, Great Plains Flora Association 1986, Gleason and Cronquist 1991, and Assigned Yatskievich 1999. Regional Abundance Frequency in Eilers and Roosa Range Midpoint Scalar Number of Percentage Characteristic Species (%) Rare 1-10% 5% 0.7 Rare to infrequent 1.4 Habit (exclusive)a Infrequent 11-30% 20% 2.8 annual 37 60.7 Infrequent to frequent 4.1 tufted 30 81.1 Frequent 31-60% 45% 6.2 Frequent to common tuft/mat 3 8.1 8.3 solitary 4 10.8 Common 61-100% 80% 11 perennial 25 41.0 clumped 13 52.0 rhizomatous 9 36.0 tuft 3 12.0 Origin (non-exclusive) 20 Europe 48 78.7 Asia 29 47.5 Africa 8 13.1 g 15 North America 5 8.2 " ~" Use (non-exclusive, except for the "none" category) u.. 10 forage 22 36.1 grain 10 16.4 5 lawn 9 14.8 revegetation 8 13.1 0 birdseed 2 3.3 1-7 7-14 14-26 26-38 38-57 57-76 76-100 ornamental 2 3.3 (R) (Rto I) (I) (I to F) (F) (FtoC) (C) none (accidental) 24 39.3 Abundance Indices and Categories Photosynthesis (exclusive) C3 38 62.3 Fig. 1. Frequency histogram of abundance index values for all 61 C4 23 37.7 species of introduced graminoids in Iowa. Abundance categories in clude rare (R), infrequent (I), frequent (F), and common (C). Compiled aExclusive (meaning species can only be in one category) except for from information in Eilers and Roosa (1994). See the text for a de Lolium perenne, which is segregated into a perennial and annual sub scription of the method used to derive the abundance index. species

an abundance index of 14 or less (are in the bottom two categories, DISTRIBUTION AND ABUNDANCE Fig. 1) and represent sporadic populations. Eighteen species are com monly encountered (are in the top two categories, Fig. 1) and account Data on the distribution and abundance of species presented in for 77% of the relative abundance index of all non-native graminoids. Eilers and Roosa (1994) were used to calculate an abundance index Thus the majority of exotic grasses are very limited in occurrence for each of the species that represents its general occurrence through (many are represented by just one historical record) and do not pre out the state. They divide the state into nine regions and, based on sent any important ecological threats. Among those species with herbaria and floristic records, assign one of these four levels of abun abundance indices over 38 (i.e., a rating of at least frequent), most dance for a species in each region: rare, infrequent, occasional, com are very familiar species (Table 3); nine are perennial C3 species, mon. Scalars were devised that represent the midpoint of the range seven are annual C4 species, and three are annual C3 species. of frequencies (for example in random community samples) implied by each of these subjective categories (Table 2). The scalars were SPECIES BIOLOGY FOR SELECTED added for all nine regions and then added to a value of 1. In this NON-NATIVE GRASSES way a species listed as common in each region of the state receives the maximum index of 100. A species listed as rare in just one region Orchard grass (Dactylis glomerata) and timothy (Phleum pratense) received the minimum index of 1.7. All other possible distributions were listed as common statewide by Eilers and Roosa (1994), but in have an abundance index between 1.7 and 100. my experience neither one is as common a species as smooth brome Nearly all of the introduced graminoids fall into one of two (Bromus inermis) and Kentucky bluegrass (Poa pratensis). Therefore groups--either they are very uncommon and known only from three both were lowered to a frequent rating in the northern and central or less of the nine geographical regions in the state (33% of the regions and a frequent to common rating in the southern regions, species), or they are widespread and are present in at least seven or resulting in a state-wide index of 63. Both species are often used in more of these regions (64%). Over half of them (32 or 52%) have pasture mixes that are sometimes mown for hay. 144 JOUR. IOWA ACAD. SCI. 108(2001)

Table 3. Non-native graminoids with an Iowa abundance index greater than 38.

Index = 76 to 100 Index = 57 to 76 Index = 38 to 57 Common Frequent to Common Frequent

Quackgrass Japanese brome Canada bluegrass Agropyron repens Bromus japonicus Poa compressa Red top Downy brome Agrostis gigantea Bromus tectorum Smooth brome Smooth crabgrass Bromus inermis Digitaria ischaemum Hairy crabgrass Annual bluegrass Digitaria sanguinea Poa annua Barnyard grass Tall fescue Echinochloa crusgali Fescue arundinacea Stinkgrass Orchard grass Erigrostis cilianensis Dactylis glomerata Kentucky bluegrass Reed canary Poa pratensis Phalaris arundinacea Yellow foxtail Timothy Setaria glauca Phleum pratensis Green foxtail Giant foxtail Setaria viridis Setaria faberii

Tall and meadow fescue are the two most common species of the mon. Both are winter annuals, which means they mature seeds in three introduced fescues, and they are similar enough that identifi early summer and require warm summer temperatures to break seed cation is problematic. Eilers and Roosa (1994) indicate that meadow dormancy. Germination occurs in the fall as temperatures cool. High fescue (Festuca pratensis) is the more abundant species. Tall fescue (F. est germination rates occurred at 15°C for both downy brome (Hul arundinacea) is a more recent introduction though and has become bert 1955) and Japanese brome (Baskin and Baskin 1981). Longevity widely used because it is more drought resistant. In my experience studies with related species (B. mo/tis, B. secalinus) indicate the seeds it is probably the more common of the two species. However, in of these winter annuals are not viable for more than 1 year (Lewis accurate vegetative identification could account for some of this per 1973, Beal 1911). Both species inhabit dry soils with low fertility, ception. The two species together seem to be at least as common as and are especially frequent in eroded or overgrazed areas. Downy orchard grass, especially in the south and east, so the regional abun brome is especially common on sandy soils. Their winter annual dances for tall fescue were revised upward resulting in a much higher habit allows them to establish in fall and have an advanced start on index(= 65) than Eilers and Roosa (1994) indicate(= 3). Both are growth in the spring when moisture conditions are favorable. By likely under collected, therefore herbaria vouchers do not indicate an maturing, dying and drying out by mid-summer, they provide fuel accurate distribution and abundance. Ecologically the two species are that promotes fires and microclimate conditions favoring their ger similar; they both have a preference for damp soil and semi-disturbed mination in the fall. habitats. Smooth brome is a strongly rhizomatous perennial species capable Hairy crabgrass (Digitaria sanguinalis) and smooth crabgrass (D. of forming a sod. It has become one of the most widespread and ischaemum) are both C4 summer annuals that are common weeds in common exotic grasses since its introduction in North America by lawns and other open disturbed areas. Their seeds germinate with the California experiment station in 1884 (Archer and Branch 1953). the advent of warm summer temperatures (maximum germination Smooth brome is a sun-loving species; seed production, tiller and at 35°C) following a period of cold stratification (Baskin and Baskin rhizome density, and biomass are reduced under shade conditions 1988, Toole and Toole 1941). The seed longevity of hairy crabgrass (Watkins 1940, Dibbern 1947). Some tolerance for dry soils has been was assessed in studies lasting for 10 and 5. 5 years, and in both cases observed and may be explained by roots reaching to a depth of nearly some seed (1 % or less) was still viable at the end of the study (Burn 1.5 m (Dibbern 1947). However, its rhizomatous sod-forming habit side et al. 1981, Egley and Chandler 1983). results in the majority of roots (64%) growing in the top 20 cm Barnyard grass (Echinochloa crusgalli) was introduced for forage and while fewer (about 21 %) occur at a depth of 40 to 100 cm (Lamba grain and is now common throughout the state. However, there is et al. 1949). This indicates that relative to native prairie grasses, the some controversy as to its taxonomic status relative to the native E. rooting pattern of smooth brome is more shallow and likely unable muricata. Some authors treat them both as subspecies of a crusgalli to compete with native C4 species in dry soils. complex, while Pohl (1966) suggested that both might be forms of Quackgrass (Agropyron repens) is the most common of the two non a native complex. Barnyard grass is listed as a facultative wetland native wheatgrasses in Iowa and tends to have a northern distribution species in the north central region by the Fish and Wildlife Service similar to the native Agropyron species. The earliest record of quack (Reed 1988). Germination studies indicate it requires cold stratifi grass for Iowa dates to 1871, and it has long been a serious agri cation and germinates best when temperatures reach 30°C (Watanabe cultural weed due i:o its strongly rhizomatous growth (Pohl 1966). and Hirokawa 1975, Barret and Wilson 1983). In a 15-year longev Toole and Brown (1946) found that less than 1 % of the seed tested ity study, seeds of barnyard grass had a maximum lifespan of 9 years in a 39"year study attained its maximum viability of 10 years. (Dawson and Bruns 1975). Reed canary has been described by some as a cryptogenic species Among the five species of annual bromes in Iowa, downy brome (i.e., a species for which the origin cannot be determined) (Carlton (Bromus tectorum) and Japanese brome (B. japonicus) are the most com- 1996). Martin and Heath (1985) consider it indigenous to temperate IOWA'S NON-NATIVE GRAMINOIDS 145

environments of all five continents. Reed canary has a long history are everywhere we look-roadsides, yards, pastures, golf courses, and of cultivation beginning in northern Europe in 1749, and cultivars parks. But they are unlike other exotic groups in that they are, for have been available across Europe since 1835 (Galatowitsch et al. the most part, planted in all these habitats. Invasive is not really an 1999). About the same time, cultivation of reed canary began in accurate description for these situations. Furthermore, many of these North America. It is possible that there are some native populations exotic grasslands provide habirat for many grassland species that for in Iowa, but most stands are more likely to be a cultivar of unknown merly occupied prairies in the state. This is especially true in south origin because it has been planted since 1900 for forage and erosion ern Iowa where there are abandoned or lightly grazed pastures cov control. The Fish and Wildlife Service list it as a facultative wetland ering many square miles. For species like the Upland Sandpiper, ( +) species for the north central region (Reed 1988), therefore it is Northern Harrier, Henslow Sparrow, and now the Greater Prairie a good indicator of wetland soils. Because of its wetland affinities Chicken, the extensive grassland structure afforded by non-native and the possibility of some native reed canary grass populations in grasslands works well as a structural substitute for native prairie. Iowa, exotic reed canary does not appear to be as common as Ken Still there is often a desire or need to improve the quality of tucky bluegrass or smooth brome, so its abundance was reduced from natural areas by controlling these exotic species. There are three pri common in all nine regions (Eilers and Roosa 1994) to frequent to mary control methods that have been evaluated in the literature common in the southeastern third of the state and frequent else fire, mowing, and herbicides. In addition, three secondary techniques where. have special application for the most troublesome and invasive spe Kentucky bluegrass is likely the most common perennial plant in cies-reed canary grass. These include artificial shading, soil removal, the state and was once commercially grown in the southern counties and flooding. for seed production. Its congener, Canada bluegrass (P. compressa), is Relevant literature was reviewed and summarized by tallying the more often found (and planted) on drier more sterile soils. Canada number of cases in which an independent assessment or observation bluegrass is also less common than Kentucky bluegrass, so the abun of a treatment's effect on a species could be ascertained. Two out dance for Canada bluegrass was downgraded from common in all comes were considered: results that indicated a treatment had no nine regions (Eilers and Roosa 1994) to infrequent in central and controlling effect (no change or an increase in abundance) or results north-central Iowa and frequent elsewhere. Kentucky bluegrass is that indicated a treatment had a controlling effect (decrease in abun another example of a cryptogenic species. There is speculation that dance). An individual study may present as many as 4 or 5 cases for it could be native to North America across the northern tier of states a single species, because a species' response was often evaluated more and Canada (Great Plains Flora Association 1986, Gleason and Cron than once over a period of time or under different treatment con quist 1991). Others describe it as native to Eurasia and introduced ditions (e.g., seasonality or intensity of application). Also, species throughout North America (Hitchcock 1950, Mohlenbrock 1972). responses may have been measured with more than one variable, such Kentucky bluegrass is strongly rhizomatous and forms a dense sod. as cover, biomass, or stem density. Results can vary depending on The rhizomes can extend its horizontal growth as much as 2 m2 in the variable used. For example, a treatment could decrease the bio two years (Kannenberg and Wrede 1934). The rhizomatous sod mass but not the density of a species. Biomass was the most common forming habit increases its competitive ability and allows it to pen variable used in the studies reviewed. It assesses a species' overall etrate between other plants in natural habitats. Both Kentucky and vigor and functional role in the community while density conveys Canada bluegrass are tolerant of successive defoliations (either graz information more related to population size and frequency of indi ing or mowing) because growth primarily occurs as elongation of viduals. Two levels of scientific rigor were recognized in the studies leaves and sheaths. Very little internode elongation occurs, which reviewed. Those classified as experimental were designed with con results in the shoot apex remaining in a lower more protected lo trols and replication sufficient to do statistical analyses. These rep cation (Etter 1951). Toole and Brown (1946) found that about 1% resent statistically significant results. Observational studies are either of the Kentucky bluegrass seed tested had longevity of 39 years, anecdotal reports or studies without a statistical component. This which was the length of their study. distinction helps to provide a level of validity to the information. Three species of foxtail (giant, yellow, and green) are among the most common weeds of cropfields and open disturbed ground. Giant Use of Fire in the Control of Exotic Grasses foxtail (Setaria faberi) is the most recent introduction of the three. It was probably introduced to the U.S. as a contaminant in grain dur Decades of research on the effects of fire on grassland communities ing the 1920s; it was first recorded in southern Iowa in 1949 (Pohl and species biology have been reported in an enormous amount of 1966). Its distribution in Iowa is across the southern half of the scientific literature. Indeed, much work has been directed towards state, while yellow foxtail (S. glauca) and green foxtail (S. viridis) are the goal of using fire to control exotic species and enhance native common statewide. All three species are capable of forming relatively species. In the 25 studies reviewed and summarized (Table 4), there persistent seed banks and seed longevity of up to 40 years has been were a few more cases of no controlling effect (53) than there were reported (Toole and Brown 1946). cases of decreases (47). Among Iowa's exotic grasses, smooth brome The last species has an abundance index less than 38, but is in and Kentucky bluegrass have been the most frequently studied spe cluded because of its potential to be an invasive species. Silver plume cies. For both species fire has been effective in about 50% of the grass (Miscanthus sacchariflorus) is mostly seen in locations where it cases, and at least for these two species, the most effective use of fire has obviously been planted (along fences and roadsides associated occurs when used in late spring (e.g., early May). Willson and Stub with farmyards). However, more frequently stands that represent an bendieck (1997) demonstrated that brome suffered the most stress "escape" are observed. It appears capable of forming extremely large when burned during tiller elongation (about mid May in Nebraska). and dense colonies and therefore could be very destructive if it es No effect was seen if burned during tiller emergence (during late tablishes in native prairie. Silver plume grass appears to favor wet March through early April). Another important pattern is a greater or damp soil. reduction if the burn occurs in a dry year (Rosburg 1990, Blankes poor and Bich 1991, Blankespoor and Larson 1994). The additional CONTROL OF INTRODUCED GRASSES stresses of low moisture and high temperatures would favor an in As a group the exotic grasses probably represent the highest crease in the rate of photorespiration in these cool-season species amount of biomass in the state among any taxonomic group. They (photorespiration represents an energy loss). 146 )OUR. IOWA ACAD. SCI. 108(2001)

Table 4. The number of cases or instances of fire having either Table 5. The number of cases or instances of mowing having no controlling effect (no change or increase) or a significant either no controlling effect (no change or increase) or a signif controlling effect (decrease) on non-native grasses in either ex icant controlling effect (decrease) on non-native grasses in ei perimental (exp) or observational/anecdotal (obs) studies. The ther experimental (exp) or observational/anecdotal (obs) stud total number of cases for either result is also expressed as a ies. The total number of cases for either result is also expressed percentage of all cases observed for the species. A total of 103 as a percentage (pct) of all cases observed for the species. A cases among these eight species were reported in 25a different total of 22 cases were described among these six species in 8 studies. different reports.a

No Change or No Change or Increase Decrease Increase Decrease Species Exp Obs Pct(%) Exp Obs Pct(%) Species Exp Obs Pct(%) Exp Obs Pct(%)

Smooth brome 18 0 50 17 1 50 Fescue 2 3 100 0 0 0 Kentucky bluegrass 10 2 43 10 6 57 Smooth brome 3 0 75 1 0 25 Fescue 9 2 85 1 1 15 Kentucky bluegrass 2 2 100 0 0 0 Japanese brome 3 0 33 6 0 67 Foxtail 2 0 67 0 1 33 Red top 6 0 100 0 0 0 Reed canary 0 1 25 0 3 75 Quackgrass 1 0 25 1 2 75 Quackgrass 0 1 50 0 1 50 Canada bluegrass 3 0 100 0 0 0 ALL SPECIES 9 7 73 1 5 27 Reed canary 0 1 25 0 3 75 ALL SPECIES 50 5 53 35 13 47 acompiled from: Diboll 1986, Apfelbaum and Sams 1987, Hutch ison 1992a, Gillespie and Mum 1992, Willson and Stubbendieck acompiled from: Launchbaugh 1964, Old 1969, Zedler and Loucks 1996, Hall 1998, Rosburg 2000 and Kurtz 2001 1969, Hadley 1970, Hill and Platt 1975, Svedarsky and Buckley 1975, Antos et al. 1983, Nagel 1983, White and Currie 1983, Engle and Bultsma 1984, Schaer and Stubbendieck 1985, Diboll 1986, be a major stress and might make the plants more susceptible to the Gartner et al. 1986, Henderson 1990, Hutchison 1992a, 1992b, stresses they confront during winter. Rosburg 1990, 2000; Whisenant and Uresk 1990, Blankenspoor and For Japanese brome, fire always resulted in significant decreases Bich 1991, Anderson 1994, Blankenspoor and Larson 1994, Gilz the first year after the burn, but by the second or third years there and Romo 1994, 1995; Willson and Srubbendieck 1996, 1997 was no difference (Whisenant and Uresk 1990). Fire will cause im mediate mortality to these winter annuals, but it can also encourage subsequent seed germination, which is beneficial for Japanese brome. Although fire can be used for short-term control of annuals, long Another important source of variation in the response of these term control with fire is problematic. Fire would need to be used species to fire is the potential amount of interspecific competition annually so that each year's cohort of germinating plants are killed that occurs after the fire. In at least five of the no change cases, there before they produce seed, but there may not be enough fuel to allow was not a significant warm-season component in the grassland-one annual burns. However, if there is enough productivity to produce was a smooth brome grassland and four were northern fescue grass fuels, properly timed annual fires can contribute to the removal of lands. The stress of photorespiration combined with the effects of an annual from the seed bank by promoting seed germination and competition from invigorated warm-season native grasses is more preventing seed production. likely to induce mortality in the exotic grasses. Therefore the lack Reed canary grass is among the most invasive of the introduced of a warm-season element provides a possible explanation for the lack graminoids, yet there has been very little experimental research on of a decrease in some cases. the use of fire for its control. The three cases of decrease in reed Three species-fescue, redtop and Canada bluegrass-were not ef canary were all anecdotal reports. One suggested that repeated fire fectively controlled by fire in the studies reviewed. Apparently these (either in late fall or late spring) over several seasons causes a decrease species are either more tolerant of fire, or the fire was not used in in biomass and that fire is most effective if fire-adapted native species the most effective manner. Timing of the fire is the single most are also present to add a component of competition during the re important factor determining the effect of fire on a plant species, covery period after the fire. Henderson (1990) (Hutchison 1992a) and, in general, most studies have focused on early- to mid-spring reported that late spring fire (late May) was effective in weakening fires, which may be too early in the season. For fire to be an effective reed canary grass in a degraded savanna in Wisconsin, however, de deterrent of a perennial species, two effects need to be maximized. sirable native species were also negatively affected. One is that the fire should occur when the direct effects of the fire (topkilling caused by the heat) will have maximum effect. For pe Use of Mowing in the Control of Exotic Grasses rennial herbaceous plants, this is after a period of substantial growth has occurred and the plant is physiologically active. The second goal The work that has been done and reported on the use of mowing is to maximize the indirect negative effects of the fire. The environ to suppress exotic grasses-represented here by eight studies-sug ment that these perennial plants experience after the fire and during gests little benefit (16 reports of no change and six reports of a the time that energy is allocated for recovery is equally important. decrease of which only one was experimental) (Table 5). This is not For example, Rosburg (2000) reported that a late fall fire (mid No a surprise given the adaptations grasses have for grazing (e.g., inter vember) was successful in reducing stem density of fescue on a prairie calary meristems) and their widespread use in hayfields. The peren reconstruction. For some C3 species, the cool weather during autumn nial grasses that have evolved with herbivores are not particularly may be a critical time for physiological activity and energy acqui vulnerable to cutting whether it is from animals or machines. Of sition prior to winter dormancy. Topkilling during this time would course mowing does reduce living biomass for several weeks right IOWA'S NON-NATIVE GRAMINOIDS 147

Table 6. The number of cases or instances of herbicides hav Samson and Moser (1982) showed that broadcasting the herbicide ing either no controlling effect (no change or increase) or a glyphosate was more effective than banding (applying in strips cen significant controlling effect (decrease) on non-native grasses in tered on the rows) when using herbicide to prepare a seedbed for either experimental (exp) or observational/anecdotal (obs) stud drilling native grasses into cool-season pastures. Banding allowed ies. The total number of cases for either result is also expressed untreated C3 grasses to tiller with increased vigor and compete with as a percentage (pct) of all cases observed for the species. A the seeded grasses. total of 109 cases among these nine species were reported from Nearly all of the studies (at least the experimental approaches) 14 different sources.a utilized spring applications. Quite a few of the anecdotal comments suggested using fall applications. There is clearly a need for research No Change or comparing the effects of application time. Increase Decrease Anderson (1994) reported a fall application of glyphosate was ef fective in reducing smooth brome over the first growing season. Species Exp Obs Pct(%) Exp Obs Pct(%) However, that effect disappeared by the second year. Regrowth be Smooth brome 12 0 40 18 0 60 yond the first growing season was a common reason for the no Kentucky bluegrass 7 0 26 20 0 74 change results seen in the studies reviewed, even though there may Red top 5 0 42 7 0 58 have been a decrease observed the first growing season. Herbicides, Reed canary 0 0 0 0 11 100 like fire, are capable of topkilling and stressing plants the first grow Fescue 6 0 67 0 3 33 ing season after application, but the root systems tend to survive. Timothy 3 0 43 4 0 57 Successful long-term control will need to utilize repeated herbicide Canada bluegrass 3 0 50 3 0 50 applications or other types of control techniques in conjunction with Quackgrass 2 0 50 2 0 50 herbicides. Japanese brome 0 0 0 3 0 100 The only species that did not decrease at all, even in the first ALL SPECIES 38 0 35 57 14 65 growing season, in any experimental studies was fescue (these six cases represent a lack of an effect from atrazine). There are anecdotal acompiled from: Samson and Moser 1982, Waller and Schmidt reports that glyphosate applied either in spring or fall will reduce 1983, Dill et al. 1986, Apfelbaum and Sams 1987, Brejda et al. fescue and that Fusilade 2000® applied after a burn is also effective 1989, Rosburg 1990, Hutchison 1992a, 1992b; Masters et al. 1992, on fescue (Hutchison 1992b). Anderson 1994, Grilz and Romo 1995, Willson and Stubbendieck The 11 anecdotal decreases reported for reed canary grass represent 1996, Hall 1998, Wisconsin DNR 1999, and Anonymous 2000 a wide variety of herbicides and techniques. Glyphosate was sug gested if applied in late summer, then burned in the spring, and then the regrowth sprayed again (Anonymous 2000). Glyphostate was also reported as effective in killing 5-10 week seedlings, as was after the mowing takes place, and this can provide some benefit (in Amitol® (a non-selective herbicide). Plateau® was suggested in com the way of increased light levels) to a young prairie reconstruction bination with Round-up® (glyphosate) on the regrowth after a spring dominated by foxtails. However, Rosburg (2000) found that June burn (Anonymous 2000). Dalapon® (selective on monocots) is sup mowing did not change the density of foxtail stems present at the posedly effective (Wisconsin DNR 1999), as is a trio of herbicides end of the growing season. used in site preparation for forestry plantings (Arsenal AC®, Ac For reed canary grass, the reported decreases are anecdotal and cord®, and Oust®) (Hall 1998). Their use in forestry management suggest that mowing to prevent seed head formation and to open might make them good choices to use on reed canary in floodplain the soil to light is beneficial (Wisconsin DNR 1999). Repeated forests. mowing both within and among growing seasons is important. In a Two important themes emerged from the anecdotal literature on Wisconsin sedge meadow colonized by reed canary grass, native wet herbicides and reed canary grass: 1) a combination or series of stresses land species became evident after five years of twice-a-year mowing is needed to effectively stress reed canary and an herbicide can work (in early summer and in early fall) (Gillespie and Mum 1992). Mow well as one of those stresses, 2) the herbicide needs to be fairly potent ing is also often suggested as something to do in combination with to be effective, thus to protect remnant plants, it needs to be one an herbicide application or some other type of stress. that can be applied to foliage when native plants are dormant. It is important to take advantage of reed canary's C3 pathway and ten Use of Herbicides in the Control of Exotic Grasses dency to be photosynthetically active early in the spring and late in Overall there were about 71 cases of herbicides decreasing exotic the fall to achieve selectivity and avoid stressing native species. grasses as compared to only 38 instances reporting no change (Table The last three control measures (secondary techniques) were all 6). Herbicides provide the best probability of attaining desirable mentioned in reference to reed canary grass. Flooding could be used results, and the data supporting this statement are more likely to in situations where the land manager has water control structures in come from experimental studies than the data from mowing or fire place. Reed canary populations seem to be the densest in areas with studies. However, there is always a selectivity issue when using her soils that are wet or nearly saturated but not flooded with standing bicides. If the exotic grasses occur in a community with desirable water (Nitz 2000). It appears that seedlings and young tillers are species, herbicide use becomes more logistically challenging. Pre intolerant to deep water. Land practices that have lowered the water venting herbicide damage to native species is one of the biggest table (e.g., tiling), especially in temporarily and seasonally flooded problems in their use in the management of natural areas. wetlands, may be one of the anthropogenic factors that has most The two herbicides that have been most studied as methods to contributed to the invasiveness of reed canary. Flooding infestations control exotic grasses are atrazine and glyphosate. Both have been at the proper time could be helpful, especially if mowing, burning very effective. Atrazine has the advantage that warm-season grasses or herbicide is used to achieve a topkill and the regrowth flooded and other deep-rooted native perennials exhibit some tolerance, with 30 cm of water. whereas glyphosate will probably at least topkill anything it con Shading was mentioned inasmuch as reed canary seems to prefer tacts. full sunlight, so anything that favors native species and that causes 148 JOUR. IOWA ACAD. SCI. 108(2001)

shading on reed canary should help. There was also a report of suc 1981. Germination of exhumed weed seed in Nebraska. Weed Science cessfully using black plastic to smother small isolated stands of reed 29:577-586. canary (Wisconsin DNR 1999). Black plastic apparently works well CARLTON, J. T. 1996. Biological invasions and cryptogenic species. Ecol in upland habitats, and particularly if used for three years and then ogy 77:1653-1654. CORRELL, D. S., and M. C. JOHNSTON. 1970. Manual of the vascular seeded with native species (Henderson 1990). Wet habitats may be plants of Texas. Texas Research Foundation, Renner, Texas. more problematic due to water displacing the plastic and more vig DAWSON, J. H., and V. F. BRUNS. 1975. Longevity of barnyard grass, orous shoots growing through the plastic (Gillespie and Mum 1992). green foxtail and yellow foxtail seeds in soil. Weed Science 23:437-440. Finally, a method of last resort is removal of the soil containing DIBBERN, J.C. 1947. Vegetative response of Bromus inermis to certain var the stand of reed canary. There was one report of some success with iations in environment. Botanical Gazette 109:44-58. this technique and a comment that an additional benefit was that DIBOLL, N. 1986. Mowing as an alternative to spring burning for control the old seed bank was exposed and provided for the establishment of cool season exotic grasses in prairie grass plantings. Pages 204-209. of native species that had not been observed on the site for a long In Proceedings of the Ninth North American Prairie Conference. G. K. time (Nitz 2000). This technique would be applicable in situations Clambey and R. H. Pemble, eds. Tri-College Press, North Dakota State University, Fargo, North Dakota. where siltation has provided reed canary an opportunity to invade a DILL, T. 0., S. S. WALLER, K. P. VOGEL, R. N. GATES, and W. W. natural area. STROUP. 1986. Renovation of seeded warm-season pastures with atra zine. Journal of Range Management 39(1):72-75. ACKNOWLEDGEMENTS EGLEY, G. H., and J.M. CHANDLER. 1983. Longevity of weed seeds after 5.5 years in the Stoneville 50-year buried-seed study. Weed Science 31: I am grateful to Lynn Clark for taking time to review a draft of 264-70. this manuscript and contributing many good suggestions for im EILERS, 1. J., and D. M. ROOSA. 1994. The vascular plants of Iowa: An provement. Over the last 15 years, the support for the research that annotated checklist and natural history. University of Iowa Press, Iowa has enabled me to investigate effects of fire and herbicides on grass City, Iowa. ENGLE D. M., and P. M. BULTSMA. 1984. Burning of northern mixed land communities and to review its large body of literature has come prairie during drought. Journal of Range Management 37(5):398-401. from the Iowa Department of Transportation (Roadside Development ETTER, A. G. 1951. How Kentucky bluegrass grows. Annual Missouri Section) and the Southern Iowa Agriculture Boosters in association Botanical Garden 38:293-375. with the Southern Iowa Resource and Conservation Development GALATOWITSCH, S. M., N. 0. ANDERSON, and P. D. ASCHER. 1999. agency. Invasiveness in wetland plants in temperate North America. Wetlands 19(4):733-755. LITERATURE CITED GARTNER, F. R., J. R. LINDSEY, and E. M. WHITE. 1986. Vegetation responses to spring burning in western South Dakota. Pages 143-146. ANDERSON, B. 1994. Converting smooth brome pasture ro warm-season In Proceedings of the Ninth North American Prairie Conference. G. K. grasses. Pages 157-160. In Proceedings of the Thirteenth North Amer Clambey and R. H. Pemble, eds. Tri-College Press, North Dakota State ican Prairie Conference: Spirit of the Land, Our Prairie Legacy. R. G. University, Fargo, North Dakota. Wickett, P. D. Lewis, A. Woodliffe and P. Pratt, eds. Department of GILLESPIE, J., and T. MURN. 1992. Mowing controls reed canary grass, Parks and Recreation, Windsor, Ontario, Canada. releases native wetland plants. Restoration and Management Notes 10(1): ANONYMOUS. 2000. Our-competing reed canary grass! Retrieved 2000 93-94. April l from: http://forums.gardenweb.com/forums/load/prairie/ GILZ, P. L., and J. T. ROMO. 1994. Water relations and growth of Bromus msg0109443228677.htmP6 inermis Leyss (smooth brome) following spring or autumn burning in a ANTOS, J. A., B. MCCUNE, and C. BARA. 1983. The effect of fire on an fescue prairie. American Midland Naturalist 132(2):340-348. ungrazed western Montana grassland. American Midland Naturalist GILZ, P. L., and J. T. ROMO. 1995. Management considerations for con 110(2):354-364. trolling smooth brome in fescue prairie. Natural Areas Journal 15(2): APFELBAUM, S. I., and C. E. SAMS. 1987. Ecology and control of reed 148-156. canary grass (Phalaris arundinacea L.). Natural Areas Journal 7(2):9-17. GLEASON, H. A., and A. CRONQUIST. 1991. 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April 1 from: http://www.dnr.state.wi.us/org/land/forestry/fh/weeds/ BASKIN, C. C., and J. M. BASKIN. 1988. Germination ecophysiology of reg.hem. herbaceous plant species in a temperate region. American Journal of Bot HENDERSON, R. A. 1990. Controlling reed canary grass in a degraded any 75:286-305. oak savanna. Restoration and Management Notes 8(2):123-124. BEAL, W. J. 1911. The vitality of seeds buried in the soil. Proceedings of HILL, G. R., and W. J. PLATT. 1975. Some effects of fire upon a call grass the Society for the Promotion of Agricultural Science, 3 lst annual meet prairie plant community in northwestern Iowa. Pages 103-113. In Prai ing 32:21-23. rie: A multiple view. Proceedings of the Fourth Midwest Prairie Confer BLANKESPOOR, G. W., and B. S. BICH. 1991. Kentucky bluegrass re ence. M. K. Wali, editor. University of North Dakota Press, Grand Forks, sponse to burning: Interactions between fire and soil moisture. The Prai North Dakota. rie Naturalist 23(4):181-192. HITCHCOCK, A. S. 1950. Manual of Grasses of the U.S. USDA Miscel BLANKESPOOR, G. W., and E. A. LARSON. 1994. Response of smooth laneous Publication #200. brome (Bromus inermis Leyss.) to burning under varying soil moisture HULBERT, 1. C. 1955. Ecological studies of Bromus tectorum and other an conditions. American Midland Naturalist 131(2):266-272. nual bromegrasses. Ecological Monographs, 25:181-213. BREJDA,]. J., 1. E. MOSER, S.S. WALLER, S. R. LOWRY, P. E. REECE, HUTCHISON, M. 1992a. Vegetation management guideline: Reed canary and]. T. NICHOLS. 1989. Atrazine and fertilizer effects on Sandhills grass (Phalaris arundinacea L.). Natural Areas Journal 12(3):159. subirrigated meadow. Journal of Range Management 42(2):104-108. HUTCHISON, M. 1992b. Vegetation management guideline: Fescue (Fes BURNSIDE, 0. C., C. R. FENSTER, 1. 1. EVETTS, and R. F. MUMM. tuca pratensis Huds.) Natural Areas Journal 12(3): 157-158. IOWA'S NON-NATIVE GRAMINOIDS 149

KANNENBERG and WREDE. 1934. On the tillering capacity of different SCHACT, W., and]. STUBBENDIECK. 1985. Prescribed burning in the American smooth stalked meadow grasses. Pflanzenbrau 10:478-480. loess hills mixed prairie of Southern Nebraska. Journal of Range Man KURTZ, C. 2001. A practical guide to prairie reconstruction. University of agement 38(1):47-51. Iowa Press, Iowa City, Iowa. SVEDARSKY, W. D., and P. E. BUCKLEY 1975. Some interactions of fire, LAMBA, P. S., H. L. AHLGREN, and R.]. MACKENKIRN. 1949. Root prairie and aspen in northwest Minnesota. Pages 115-121. In Prairie: A growth of alfalfa, medium red clover, bromegrass and timothy under multiple view. Proceedings of the Fourth Midwest Prairie Conference. various soil conditions. Agronomy Journal 41:451-458. M. K. Wali, editor. University of North Dakota Press, Grand Forks, LAUNCHBAUGH,]. L. 1964. Effects of early spring burning on yields of North Dakota. native vegetation. Journal of Range Management 17:5-6. SWINK, F., and G. WILHELM. 1979. Plants of the Chicago region. The LEWIS,]. 1973. Longevity of crop and weed seeds: Survival after 20 years Morron Arboretum, Lisle, Illinois. in soil. Weed Research 13, 179-91. TOOLE, E. H., and E. BROWN. 1946. Final results of the Duvel buried MARTIN, G. C., and M. E. HEATH. 1985. Reed Canary grass. Pages 207- seed experiment. Journal of Agricultural Research 72:201-210. 216. In Forages: The science of grassland agriculture. M. E. Heath, R. TOOLE, E. H., and V. K. TOOLE. 1941. Progress of germination of seed F. Barnes, and D. S. Metcalfe, eds. Iowa State University Press, Ames, of Digitaria as influenced by germination temperarure and other factors. IA. Journal of Agricultural Research 63:65-90. MASTERS, R. A., K. P. VOGEL, and R. B. MITCHELL. 1992. Response VOSS, E. G. 1972. Michigan flora-Part 1: Gymnosperms and monocots. of Central Plains tallgrass prairies to fire, fertilizer, and atrazine. Journal Cranbrook Institute of Science, Bloomfield Hills, Michigan and Univer of Range Management 45(3):291-295. sity Michigan Herbarium. MOHLENBROCK, R.H. 1972. Illustrated flora of Illinois-Grasses: Bromus WALLER, S. S., and D. K. SCHMIDT. 1983. Improvement of eastern Ne to Paspalum. Southern Illinois University Press, Carbondale, Illinois. braska tall-grass range using atrazine or glyphosate. Journal of Range NAGEL, H. G. 1983. Effect of spring burning date on mixed prairie soil Management 36(1):87-90. moisture, productivity, and plant species composition. Pages 259-263. WATANABE, Y., and F. HIROKAWA. 1975. Requirement of temperature conditions in germination of annual weeds and its relation to seasonal In Proceedings of the Seventh North American Prairie Conference. C. L. distribution of emergence in the field. Pages 38-41. In Proceedings of Kucera, editor. Southwestern Missouri State University, Springfield, Mis the Fifth Asian-Pacific Weed Science Society Conference. Tokyo, Japan. souri. WATKINS, ]. M. 1940. The growth habits and chemical composition of NITZ, M.A. 2000. Out-competing reed canary grass' Retrieved 2000 April bromegrass, Bromus inermis (Leyss), as affected by different environmental 1 from: http://forums.gardenweb.com/forums/load/prairie/msg conditions. Journal of the American Society of Agronomy 32:527-538. 0109443228677 .htmP6 WHISENANT, S. G., and D. W. URESK. 1990. Spring burning Japanese OLD, S. M. 1969. Microclimate, fire, and plant production in an Illinois brome in a western wheatgrass community. Journal of Range Manage Prairie. Ecological Monographs 39(4):355-384. ment 43(3):205-208. POHL, R. W. 1966. The grasses of Iowa. Iowa State Journal of Science 40(4): WHITER. S., and P. 0. CURRIE. 1983. Prescribed burning in the northern 341-566. Great Plains: Yield and cover responses of 3 forage species in the mixed POHL, R. W. 1987. Pennisetum petiolare, a pseudopetiolate African grass ad grass prairie. Journal of Range Management 36(2):179-183. ventive in Iowa. Proceedings of the Iowa Academy of Science 94(1):20- WILLSON G. D., and]. STUBBENDIECK. 1996. Suppression of smooth 21. brome by atrazine, mowing, and fire. The Prairie Naturalist 28(1): 13- REED, P. B. 1988. National list of plant species that occur in wetlands: 20. 1988 national summary. Biological Report 88(24), U.S. Fish and Wildlife WILLSON G. D., and ]. STUBBENDIECK. 1997. Fire effects on four Service. growth stages of smooth brome (Bromus inermis Leyss). Natural Areas ROSBURG, T. R. 1990. Resro~ation of remnant, native warm-season grasses Journal 17(4):306-312. on southern Iowa pastureland. Thesis, Iowa State University, Ames, Iowa. WISCONSIN DNR. 1999. Reed canary factsheet. Retrieved 2000 April 1 ROSBURG, T. R. 2000. The Story County Interstate 35 prairie reconstruc from: http ://www.dnr. state. wi. us/ org/land/ er I invasive/ factsheets/ reed .h cm. tion: Second year affects of fire and mowing treatments, 1997 to 1999. YATSKIEVYCH, G. 1999. Steyermark's flora of Missouri (Volume 1). Mis Addendum to Final Report-Phase One. Submitted to Living Roadway souri Department of Conservation, Jefferson City, Missouri and Missouri Trust Fund, Roadside Development Section, Iowa Department of Trans Botanical Garden Press, St. Louis, Missouri. portation, Ames, Iowa. ZEDLER, ]., and 0. L. LOUCKS. 1969. Differential burning response of SAMSON,]. F., and L. E. MOSER. 1982. Sod-seeding perennial grasses into Poa pratensis fields and Andropogon scoparius prairies in central Wisconsin. eastern Nebraska pastures. Agronomy Journal 74:1055-1060. American Midland Naturalist 81(2):341-352. 150 JOUR. IOWA ACAD. SCI. 108(2001)

Appendix A. Species data for non-native graminoids known to occur in Iowa. Habit indicates either annual (A) or perennial (P) lifespan and the type of growth form. Origin indicates the continent(s) of native distribution. Use indicates the reason for introduction-either for forage, grain production, revegetation and erosion control, turf in lawns, birdseed, or an ornamental. Photosynthetic pathway (Photo) is either cool-season (C3) or warm-season (C4). Abundance index (Al) combines the regional abundance and distribution for the species and indicates its general occurrence on a scale from 100 to 1. 7 (rounded to nearest integer). Regional distribution and abundance are data presented by Eilers and Roosa (1994) for each of the nine geographic zones in Iowa. Species are listed as rare (R), infrequent (I), frequent (F), or common (C) in each zone.

Scientific Name Common Name Habit Origin Use

Aegilops cylindrica goat grass A, tuft Europe, Asia none Agropyron cristatum crested wheatgrass P, clump Europe, Asia forage, reveg Agropyron pectiniforme* P, clump Europe, Asia forage, reveg Agropyron repens* quack grass P, rhizome Europe, Asia forage, reveg Agrostis gigantea red top P, rhizome Europe forage Agrostis stolonifera creeping bent P, clump Europe lawn Alopecurus pratensis meadow foxtail P, clump Europe, Asia forage Arrhenatherum elatius tall oatgrass P, clump Europe forage Avena fatua wild oats A, tuft Europe, Asia grain Avena sativa cultivated oats A, solitary Europe, Asia gram Bromus commutatus hairy chess A, tuft Europe, Asia none Bromus inermis smooth brome P, rhizome Europe forage Bromus japonicus Japanese brome A, tuft Europe, Asia none Bromus mollis soft chess A, tuft Europe none Bromus secalinus cheat grass A, tuft Europe none Bromus tectorum downy chess A, tuft Europe, Asia, Africa none Chloris verticillata windmill grass P, tuft N. Am none Dactylis glomerata+ orchard grass P, clump Europe forage Digitaria ciliaris southern crabgrass A, tuft/mat Europe, Africa none Digitaria ischaemum smooth crabgrass A, tuft Europe, Asia none Digitaria sanguinalis common crabgrass A, tuft/mat Europe none Echinochloa crusgalli barnyard grass A, tuft Europe, Asia forage, grain Eleusine indica goose grass A, tuft Africa none Eragrostis cilianensis stinkgrass A, tuft Europe none Eragrostis poaeoides little lovegrass A, tuft Europe none Eriochloa villosa cup grass A, tuft Asia none Festuca arundinacea+ tall fescue P, clump Europe, Asia, Africa forage, reveg Festuca pratensis meadow fescue P, clump Europe, Asia forage, reveg Festuca rubra red fescue P, rhizome N. Am, Europe, Asia lawn Heleochloa schoenoides* A, ruft/mat Europe, Africa none Holcus lanatus velvet grass P, clump Europe forage Hordeum vulgare cultivated barley A Asia gram Lolium perenne perennial rye grass A, tuft or P, clump Europe forage, reveg, lawn Lo!ium temulentum darn el A, tuft Europe, Africa none Miscanthm saccharifioms plume grass P, rhizome Asia orn. Panimm hillmanii A, tuft N. Am none Panimm miliaceum proso millet A, tuft Europe forage, grain Pennisetum petiolare A, solitary Africa birdseed Phalaris arundinacea + reed canary grass P, rhizome N. Am, Europe forage, reveg, orn. Phalaris canariensis canary grass A, tuft Europe birdseed Ph!eum pratense+ timothy P, clump Europe forage Poa annua annual bluegrass A, tuft Europe, Asia lawn Poa bulbosa bulbous bluegrass P, tuft Europe, Asia lawn Poa compressa+ Canada bluegrass P, rhizome Europe lawn, forage Poa nemoralis wood bluegrass P, tuft Europe lawn Poa pratensis Kentucky bluegrass P, rhizome Europe, Asia lawn, forage Poa trivia/is meadow grass P, clump Europe lawn Puccinellia distans European alkali grass P, clump Europe, Asia none Scirpus mucronatus bulrush A, tuft Europe, Asia none Sc!erochloa dura A, tuft Europe none Secale cereale cultivated rye A, tuft Asia grain, forage, reveg IOWA'S NON-NATIVE GRAMINOIDS 151

Appendix A. Extended.

Regional Distribution and Abundance Photo AI NW NC NE WC c EC SW SC SE

C3 3 R R R C3 5 R R R R R R C3 3 R R R C3 100 c c c c c c c c c C3 100 c c c c c c c c c C3 7 R R R R R R R R R C3 2 R R C3 4 R R R R C3 7 R R R R R R R R R C3 26 I I I I I I I I I C3 26 I I I I I I I I I C3 100 c c c c c c c c c C3 76 F,C F,C F,C F,C F,C F,C F,C F,C F,C C3 2 R R C3 12 R R R R R R I R I C3 76 F,C F,C F,C F,C F,C F,C F,C F,C F,C C4 2 R R C3 63 c c c c c c c c c C4 2 R C4 76 F,C F,C F,C F,C F,C F,C F,C F,C F,C C4 100 c c c c c c c c c C4 100 c c c c c c c c c C4 30 R R R R,F R,F R,F F F F C4 100 c c c c c c c c c C4 2 R R C4 7 R R R R R R R R R C3 65 R R R C3 26 I I I I C3 3 R R R C4 2 R C3 3 R R R C3 26 I I I I I I I I I C3 23 R,I R,I R,I R,I R,I R,I R,C R,I R,I C3 2 R R C4 26 I I I C4 2 R C4 12 R,I R,I R,I R,I R,I R,I R,I R,I C4 2 R C3 63 c c c c c c c c c C3 7 R R R R R R R R R C3 63 c c c c c c c c c C3 76 F,C F,C F,C F,C F,C F,C F,C F,C F,C C3 3 R R R C3 50 c c c c c c c c c C3 2 R R C3 100 c c c c c c c c c C3 2 R R C3 2 R C3 2 R C3 2 R C3 26 I 152 JOUR. IOWA ACAD. SCI. 108(2001)

Appendix A. Continued.

Scientific Name Common Name Habit Origin Use

Setaria faberi giant foxtail A, tuft Asia none Setaria glauca yellow foxtail A, tuft Europe none Setara italica foxtail millet A, tuft Europe, Asia grain Setaria verticillata bristly foxtail A, tuft Europe none Setaria viridis green foxtail A, tuft Europe, Asia none Sorghum bicolor sorghum A, tuft Africa grain, forage Sorghum halepense johnson grass P, rhizome Europe, Asia forage Sorghum sudanense Sudan grass A, solitary forage Triticum aestivum cultivated wheat A, tuft Asia grain Zea mays cultivated corn A, tuft N.Am grain

*These species have recently undergone taxonomic revisions (Lynn Clark, Iowa State University, personal communication): Agropyron pectiniforme = Agropyron cristatum subsp. pectinatum Agropyron repens = Elymus repens Heleochloa schoenoides = Crypsis schoenoides +The abundance indices for these species are based on revised regional abundances (see text) rather than the Eilers and Roosa (1994) data IOWA'S NON-NATIVE GRAMINOIDS 153

Appendix A. Continued Extended.

Regional Distribution and Abundance Photo AI NW NC NE WC c EC SW SC SE C4 61 I I I I,C I,C I,C c c c C4 100 c c c c c c c c c C4 7 R R R R R R R R R C4 35 I,F l,F R l,F l,F l,F I,F l,F I,F C4 100 c c c c c c c c c C4 7 R R R R R R R R R C4 3 R R R C4 7 R R R R R R R R R C3 7 R R R R R R R R R C4 26 I I I I I I I I I