<p> 1</p><p>Electronic Supplementary Material</p><p>Table S1. Site characteristics for populations of Chamaecrista fasciculata considered in the study.</p><p>Population Location Site Characteristics Plants associated Setting</p><p>Sac Prairie Cuivre River State Tall grass prairie under Dominated by Andropogon (SAC) Park, near Troy, MO restoration. gerardii (big bluestem) and Rural Sorghastrum nutans (indian grass).</p><p>Big Sugar Cuivre River State Open roadside area. Dominated by A. gerardii Rural Creek Park, near Troy, MO (big bluestem) and (BSC) Sporobolus heterolepsis (prairie dropseed) and surrounded by oak forest.</p><p>Northwood Cuivre River State Native prairie Dominated by A. gerardii Rural s Prairie Park, near Troy, MO (big bluestem) and several (NWP) herbs.</p><p>Fult’s Hill Prairie A dry opening on an Dominated by Bouteloua Fult’s Hill Nature Preserve, upland forested slope curtipendula (side-oats Rural Prairie Monroe County, IL (Loess Hill Prairie) gramma), Schizachyrium (FHP) scoparium (little bluestem), A. gerardii (big bluestem), and S. nutans (indian grass).</p><p>Poag Rd. Poag Rd. and I-255, Along a dry and open Dominated by xerophytic Rural (POA) Madison County, IL sand bar, in a primary vegetation (cacti, pioneer natural plant herbs and invading oak community trees).</p><p>Horseshoe Horseshoe Lake State Along a trail on Surrounded by moist forest, Rural Lake (HSL) Park, Madison County, Walker’s island which dominated by oak trees. IL is part of a low flood plain following the Mississippi River</p><p>St. Charles St. Charles Rock Rd. Along a rocky ditch at A mixture of ornamental Urban Rock Rd. and I-170, St. Louis the St. Charles Rock and weedy vegetation. (SRR) County, MO Rd. exit of I-170. </p><p>Delmar Delmar Ave. and I- Along the Delmar exit Lawn of annual rye grass, Urban (DEL) 170, St. Louis County, of I-170 in a strip ornamental and weedy MO lawn. vegetation. 2</p><p>Table S2. Frequency distribution of samples of nectar obtained from C. fasciculata in the greenhouse study that showed various combinations of sugar types. Numbers in parentheses refer to percentages from the total number of samples (n) for each population. From all 238 samples, 53% had some form of sugar (F = fructose, G = glucose, S = sucrose), less than 1% of which were F or G only and more than 45% contained S alone or in combination with F and/or </p><p>G (refer to Fig. 1 for population names). Different superscript letters on population name indicate significant differences among populations in the proportion of samples that contain any measurable amount of sugar (for all significant difference: P < 0.05, post hoc tests were done with Tukey multiple comparisons test for proportions).</p><p>Population F only G only S only F + G S + F S + G S +F+ G Total n</p><p>SACa 0 (0) 0 (0) 6 (23.1) 0 (0) 4 (15.4) 0 (0) 8 (31.7) 18 (69.2) 26</p><p>BSCa 1 (3.3) 0 (0) 11 (36.6) 0 (0) 2 (6.6) 0 (0) 5 (16.6) 19 (63.3) 30</p><p>NWPa 0 (0) 0 (0) 7 (29.2) 0 (0) 4 (16.7) 0 (0) 4 (16.7) 15 (62.5) 24</p><p>FHPa 0 (0) 1 (3.4) 14 (48.3) 1 (3.4) 1 (3.4) 0 (0) 4 (13.8) 21 (72.4) 29</p><p>POAb 0 (0) 0 (0) 14 (37.8) 0 (0) 2 (5.4) 0 (0) 1 (2.7) 17 (45.9) 37</p><p>HSLb 0 (0) 0 (0) 7 (23.3) 0 (0) 0 (0) 0 (0) 2 (6.6) 9 (30.0) 30</p><p>DELa 0 (0) 0 (0) 14 (42.4) 0 (0) 3 (9.1) 0 (0) 4 (12.1) 21 (63.6) 33</p><p>SRRc 0 (0) 0 (0) 4 (13.7) 0 (0) 2 (6.9) 1 (3.4) 0 (0) 7 (24.1) 29</p><p>Total 1 (0.004) 1 (0.004) 77 (32.4) 1 (0.004) 18 (0.076) 1 (0.004) 28 (11.8) 127 (53.4) 238 3</p><p>Table S3. Composition of ant and herbivore communities on census plants of C. fasciculata. </p><p>These are the species names for those found in the 30 plants per population in June and August </p><p>2001. Numbers indicate the total number of individuals lumped for all plants across both censuses. Refer to Fig. 1 for population names. </p><p>SAC BSC NWP FHP POA HSL SRR DEL Total ANTS Monomorium 45 61 13 37 738 205 3 6 1108 minimum (Buckley) Tetramorium - - 2 12 - - - 2 16 tsushimae (Emery) Forelius pruinosus 2 5 - - 22 - - - 29 (Roger) Tapinoma sessile - - - - - 12 - - 12 (Say) Paratrechina - 3 - - - - - 2 5 terrícola (Buckley) Crematogaster 5 3 23 15 - 5 1 - 52 lineolata (Say) Formica subsericea - 7 - 5 1 2 - - 15 (Say) Camponotus - - 2 - - 19 - - 21 americanus (Mayr) Total 52 79 40 69 761 243 4 10 1258 HERBIVORES Eurema lisa 7 - 1 7 2 3 - - 20 Phoebis sennae - - - - 2 14 - - 16 Polyhymno 4 1 3 3 2 3 - - 16 luteostrigella Orthopteran 1 8 1 - 1 2 2 - 15 Curculionid beetles 1 5 10 7 6 2 6 - 37 Homopteran - 3 12 - 5 7 3 2 32 Unidentified 2 8 13 6 2 2 2 2 37 geometrids Unidentified - 1 2 - 3 2 1 - 9 parasitoids Unidentified stem - - - - 7 - - - 7 borers Total 15 26 42 23 30 35 14 4 189 4</p><p>Fig. S1. Density of insects recorded on plants of C. fasciculata across populations on June </p><p>(census 1) and August (census 2) 2001. a) Mean density of ants, b) leaf chewing herbivore density, c) total herbivore density and d) lepidopteran egg density (refer to Fig. 1 for population names). Different letters indicate significant differences among populations within each census </p><p>(for all significant difference: p < 0.05, post hoc tests were done with Tukey nonparametric multiple comparisons test). Bars represent one SE of the mean.</p>