Caesalpinioideae is the second largest subfamily of legumes (Leguminosae) with ca. 4680 species and 163 genera. It is an ecologically and economically important group formed of mostly woody perennials that range from large canopy emergent trees to functionally herbaceous geoxyles, lianas and shrubs, and which has a global distribution, occurring on every continent except Antarctica. Following the recent re -circumscription of 15 Caesalpinioideae genera as presented in Advances in Legume Systematics 14, Part 1, and using as a basis a phylogenomic analysis of 997 nuclear gene sequences for 420 species and all but five of the genera currently recognised in the subfamily, we present a new higher -level classification for the subfamily. The new classification of Caesalpinioideae comprises eleven tribes, all of which are either new, reinstated or re -circumscribed at this rank: Caesalpinieae Rchb. (27 genera / ca. 223 species), Campsiandreae LPWG (2 / 5-22), Cassieae Bronn (7 / 695), Ceratonieae Rchb. (4 / 6), Dimorphandreae Benth. (4 / 35), Erythrophleeae LPWG (2 /13), Gleditsieae Nakai (3 / 20), Mimoseae Bronn (100 / ca. 3510), Pterogyneae LPWG (1 / 1), Schizolobieae Nakai (8 / 42-43), Sclerolobieae Benth. & Hook. f. (5 / ca. 113). Although many of these lineages have been recognised and named in the past, either as tribes or informal generic groups, their circumscriptions have varied widely and changed over the past decades, such that all the tribes described here differ in generic membership from those previously recognised. Importantly, the approximately 3500 species and 100 genera of the former subfamily Mimosoideae are now placed in the reinstated, but newly circumscribed, tribe Mimoseae. Because of the large size and ecological importance of the tribe, we also provide a clade-based classification system for Mimoseae that includes 17 named lower -level clades. Fourteen of the 100 Mimoseae genera remain unplaced in these lower -level clades: eight are resolved in two grades and six are phylogenetically isolated monogeneric lineages. In addition to the new classification, we provide a key to genera, morphological descriptions and notes for all 163 genera, all tribes, and all named clades. The diversity of growth forms, foliage, flowers and fruits are illustrated for all genera, and for each genus we also provide a distribution map, based on quality-controlled herbarium specimen localities. A glossary for specialised terms used in legume morphology is provided. This new phylogenetically based classification of Caesalpinioideae provides a solid system for communication and a framework for downstream analyses of biogeography, trait evolution and diversification, as well as for taxonomic revision of still understudied genera.

Senegalia comprises 219 species distributed in tropical and subtropical regions of North and South America, Africa, Asia and Australia. Two sections are currently recognised within Senegalia and these are most readily distinguished by the differences in disposition of their cauline prickles, i.e. sect. Senegalia with prickles at or near leaf nodes and sect. Monacanthea with mostly internodal prickles. Previous phylogenetic studies, based primarily on small numbers of plastid DNA loci, found Senegalia to be monophyletic with two large subclades corresponding to the sections. Here, we present new phylogenomic evidence from 997 single-copy nuclear gene sequences for a small, but representative set of species. These new analyses show that Senegalia is non-monophyletic, but instead, forms a grade that is paraphyletic with respect to the remainder of the ingoid clade (i.e. Ingeae + Acacia s.s. + Acaciella), comprising two well-supported subclades most likely representing the same clades as found in previous phylogenetic studies of the genus and, interspersed between these, a third, moderately supported clade, comprising the genera Mariosousa, Pseudosenegalia and Parasenegalia. In marked contrast to the nuclear phylogeny, the two Senegalia clades are sister groups in the plastid phylogeny, based on analyses of 72 chloroplast genes, rendering the genus monophyletic, based on plastid data alone. We discuss this new evidence that Senegalia is non-monophyletic in relation to the marked cytonuclear discordance, high gene tree conflict and lack of resolution across this senegalioid grade and review the consistency of the key morphological characters distinguishing the two sections of Senegalia. We conclude that it is likely that Senegalia will need to be split into two (or possibly more) genera: a re-circumscribed Senegalia s.s. that corresponds to the existing Senegalia sect. Senegalia plus the S. ataxacantha group (Senegalia sect. Monacanthea s.s.; future studies may show that this group warrants generic status) and a new genus corresponding to the remainder of sect. Monacanthea (here designated as Senegalia sect. Monacanthea p.p.). However, re-delimiting Senegalia now would be premature given that the key morphological characters are not fully congruent with the two sections and pending denser phylogenetic sampling of taxa. A judiciously selected list of critical taxa is presented to facilitate future phylogenomic studies. Finally, we discuss the identity of Albizia leonardii, which is also placed in this senegalioid grade in these new phylogenomic analyses and place it in synonymy with Parasenegalia vogeliana.

ABSTRACT We conducted literature searches of records from Illinois, Indiana, Iowa, Minnesota, Missouri, North Dakota, Ohio, and Wisconsin to create a source bibliography of wildland fire descriptions occurring between 1673 and 1905. A total of 795 landscape fire records were identified within or near the eastern tallgrass prairie–forest transition region, including 32 attributed to Native Americans, 194 to Europeans from spontaneous records in the nineteenth century, and 569 to Europeans from a systematic dataset collected during the late nineteenth and early twentieth centuries in Minnesota. From these historical accounts, we find overwhelming evidence that a two- to three-week period during October and November, known then as “Indian summer,” was the primary wildland fire season. Our records indicate that Native Americans used fire primarily for hunting, whereas Euro-American fires were set to reduce fire hazards near their habitations, to eliminate crop residues, and to facilitate plowing, or they were escapes due to mere carelessness. Only five lightning-caused fires were identified. Individual fires frequently burned thousands of hectares, creating dense smoke, damaging trees, personal property, and occasionally burning inhabitants fatally. South and southwest were the most frequent wind directions during wildfires. Drought years, including 1796, 1819, 1856, and 1871, were characterized by extensive fires, which ultimately resulted in legislation to protect property owners and public welfare. Fire events for the study period are certainly underestimated by this dataset because only large, spectacular, threatening fires were recorded, especially during European settlement. In addition, our estimate of Native American fire frequency and prevalence is less than their historical/expected frequency, due to their widespread population collapse and changed hunting methods following contact and dispossession by Europeans.

We conducted field searches for populations of Mentzelia oligosperma Nutt. (stickleaf) throughout the known range of this species in Illinois during the growing seasons of 2010–2019. A species common to the prairies and plains of western North America, it is habitat-specific and rarely observed in Illinois. Populations are confined mostly to narrow limestone cliff ledges along the bluffs of the Mississippi River in Adams, Calhoun, Monroe, Pike, and Randolph counties on the western border of the state. We identified 18 potential stickleaf sites based upon herbaria searches and interviews with biologists. Subsequent field investigations determined the presence of 15 extant sites, including two new locations at Hull in Pike County and the Fults Hill Prairie Annex in Monroe County. Five historic populations are extirpated. The state total of 498 plants represents populations ranging from six to 85 individuals at 15 sites, with most locations having fewer than 20 individuals. Stickleaf is currently listed as endangered by the Illinois Endangered Species Protection Board due to its restricted habitat and low population densities.

A second population of Phemeranthus calycinus (Montiaceae, large-flowered rock pink) was confirmed for southwestern Illinois. This is the second site known east of the Mississippi River for this taxon.

ABSTRACT Large expanses of loess hill prairie were once common along the bluffs of the Mississippi and Illinois rivers of Illinois. These communities occur in forest openings on thick loess deposits overlying bedrock and frequently have expanses of exposed limestone at their margins (glades). Warm season, clump-forming grasses dominate the herbaceous vegetation along with a mixture of prairie and open forest species. Miles Hill Prairie, Monroe County, Illinois is located about 20 km west of Waterloo in the Northern Section of the Ozark Natural Division. Within the prairie, 148 vascular plant species were recorded with 40 species found in the survey plots. Schizachyrium scoparium dominated followed by Andropogon gerardii, Solidago speciosa, Sorghastrum nutans, and Bouteloua curtipendula. Common forbs include Pycnanthemum pilosum, Symphotrichum patens, and Symphotrichum oolentangiense with Cornus drummondii the most abundant shrub, and Torilis japonica the only exotic species in plots. This is a high-quality loess hill prairie that is well maintained by prescribed fire and brush removal. Most species encountered were common to loess hill prairies, with the 19 exotic species being rare and mostly restricted to prairie edges.

Recent studies have shown that the genus Acacia Mill. s.l. is polyphyletic, consisting of at least seven distinct groups of species. One of these groups, the proposed genus Parasenegalia Seigler & Ebinger, consists of seven species. We describe a new species, Parasenegalia lundellii Seigler & Ebinger, and make the following new combinations: Parasenegalia muricata (L.) Seigler & Ebinger, Parasenegalia rurrenabaqueana (Rusby) Seigler & Ebinger, Porasenegalia santosii (G. P. Lewis) Seigler & Ebinger, Parasenegalia skleroxyla (Tussac) Seigler & Ebinger, Parasenegalia visco (Lorentz ex Griseb.) Seigler & Ebinger, and Parasenegalia vogeliana (Steud.) Seigler & Ebinger. A second proposed genus, Pseudosenegalia Seigler & Ebinger, consists of two species: Pseudosenegalia feddeana (Harms) Seigler & Ebinger and Pseudosenegatia riograndensis (Atahuachi & L. Rico) Seigler & Ebinger. The species of Parasenegalia are widespread in the tropical areas of the Caribbean and scattered in Central and South America. Those of Pseudosenegalia are found in Bolivia. A series of morphological characteristics, as well as recent molecular data, separate these new genera from other members of Acacia subg. Aculciferum Vassal. Although members of these two genera are distinct, previous taxonomic treatments have not dealt with them as separate units within Acacia subg. Aculeiferum. Lectotypes are designated for the following names: Acacia concinna Phil., Acacia polyphylla Clos, Acacia riparia Kunth var. angustifoliola Kuntze, Parasenegalia visco (Lorentz ex Griseb.) Seigler & Ebinger [equivalent to Acacia. visco Lorentz ex Griseb.], and Pseudosenegalia feddeana (Harms) Seigler & Ebinger [equivalent to Acacia feddeana Harms].

Studies have shown that the genus Acacia Miller s. l. is polyphyletic, consisting of at least seven distinct groups of species. One of these major groups, Senegalia s. l., was also determined to be non-monophyletic. This has resulted in the recent recognition of two new genera, Parasenegalia Seigler and Ebinger, consisting of seven species, and Pseudosenegalia Seigler and Ebinger, consisting of two species. A molecular phylogenetic analysis of these genera and sister taxa, especially Mariosousa Seigler and Ebinger, determined that each is monophyletic, although Parasenegalia visco (Lorentz and Grisebach) Seigler and Ebinger is weakly supported as sister to the rest of Parasenegalia. Pseudosenegalia is sister to the rest of the ingroup, however the node containing Parasenegalia, Mariosousa, and the remaining ingroup grade of Ingeae and Acacia s. s. is poorly supported. These results provide a phylogenetic resolution for the major genera of the American species of Acacia s. l., but full phylogenetic resolution requires a subfamily-based investigation. Simple synapomorphies do not correlate with all genera and these traits are discussed in the context of the phylogeny. A key to the four genera is presented.

The extent of forest, savanna, barrens, and prairie vegetation of Crawford County, Illinois, was mapped using the General Land Office survey notes of 1804-1821. Forest vegetation was the most exten- sive, covering 40.8% of the county, followed by prairie (34.2%), savanna (18.2%) and barrens (6.8%). Quercus alba L. (white oak) was the dominant forest species with an importance value (IV) of 60.6, followed by Q. velutina Lam. (black oak), Carya spp. (hickories), Ulmus spp. (elms), and Acer saccharinum L. (silver maple). In the savanna white oak again dominated (IV of 66.2), followed by black oak and hickories. The areas designated as barrens by the surveyors were dominated by white oak (IV of 78.8) followed by hickories, black oak, Acer saccharum Marsh. (sugar maple), and Fagus grandifolia Ehrh. (beech). Density (trees/ha) was 149.7, 18.2 and 29.7 for the forest, savanna and barren areas, respectively. Corylus americana Walt. (hazelnut) had the highest frequency for understory shrubs and was commonly associated with the forest- prairie interface and barrens. Shifts in plant community boundaries occur over extended periods of time, and the knowl- edge of the presettlement vegetation can be very useful in interpreting many of these changes. In particular, a comparison of presettlement vegetation with that existing at the present time allows an estimation of the degree and direction of change during the past 150 years in central Illinois. Many of these presettlement plant communities have been destroyed with the frag- mented remains being highly modified by fire suppression, grazing, the introduction of exotic and weedy species, and in many more subtle ways by acid rain, chemical pollutants, drainage, and species extinction. General Land Office (GLO) survey notes are occasionally used to reconstruct presettle- ment vegetation, and when used with other sources, such as soil maps and early historical accounts, provide a reasonable indication of the vegetation just prior to settlement by Euro- peans (Bourdo 1956, Hutchison 1988). In Illinois, the GLO survey notes were used by Anderson (1970) to determine the extent of presettlement prairies. These notes have also been used to reconstruct the presettlement vegetation of Kane (Kilburn 1959), Lake (Moran 1976), Mason and McLean (Rodgers and Anderson 1979), Douglas (Ebinger 1986), Coles (Ebinger 1987), and Williamson (Anderson and Anderson 1975) counties, and the Mackinaw River Valley (Thomas and Anderson 1990). In the present study, the vegetation of Crawford County, Illinois was determined using GLO survey notes. Located in the Southern Till Plain and the Wabash Border Divisions of east- central Illinois (Schwegman 1973), this county has an area of 438 square miles (1134 kmi2). The Wabash River forms the eastern border while the Embarras River flows through the extreme southwest corner of the county. The first parts of the county surveyed were areas enclosed within Indian boundaries. One of these boundary lines, with a north/south orientation, divides the county roughly in half, the second with an east/west orientation divides the eastern portion into two parts (Figure 1). The first deed was recorded in the county clerk's office in 1816, however, according to Perrin (1883) there was considerable settlement prior to that date.

Dolomite prairies are rare natural plant communities, with a few high-quality examples in northeastern Illinois. In this study, three dolomite prairies located in southwestern Will County, Illinois, were surveyed to assess species composition and quality. Two of the dolomite prairies were located on the Des Plaines Wildlife Conservation Area (i.e., Blodgett Road Dolomite Prairie Natural Area and Grant Creek Nature Preserve) and the third in the Midewin National Tallgrass Prairie (i.e., Exxon Mobil Natural Area). Overall, a total of 438 taxa were recorded: 318 at Blodgett Road, 255 at Exxon Mobil, and 270 at Grant Creek, with 129 common to them all. Of these, 97 were mesic or wet prairie species, 26 were nonnative taxa, and six were native woody species. Three state endangered and two state threatened species were found associated with these dolomite prairies. The Blodgett Road site was dominated by the annual grass Sporobolus vaginiflorus, along with Andropogon gerardii, Sporobolus heterolepis, and Ambrosia artemisiifolia. The Exxon Mobil site was dominated by the exotic species Poa compressa and Daucus carota, and several native taxa including Sporobolus vaginiflorus, Allium cernuum, Andropogon gerardii, and Solidago altissima. The Grant Creek location was dominated by Sporobolus heterolepis, Rosa carolina, Sorghastrum nutans, and Solidago altissima. These three dolomite prairies can be considered good quality natural areas based on species richness and floristic quality. However, the presence and occasional dominance of nonnative species suggests the need for implementation and continuation of management practices that should maintain or improve their quality.