Phragmites australis subsp. australis is an invasive alien of major importance in natural habitats in many parts of North America but methods of distinguishing it from the native subsp. americanus required more research. A study of the value of basal stem internode color was conducted in eastern Ontario where the long history of collections enables characteristics of the native subspecies to be evaluated, since the invasive alien subspecies is believed to have arrived only recently. Although there is some overlap, correlation analysis indicated that basal stem internode color was highly correlated with ligule height and lower glume length, the latter characters being considered the most important for differentiation. With regard to ligule height, a measurement excluding the fringe of hair proved most valuable. Collections of native plants prior to the post-1970 spread of Phragmites along roads have reddish-purple lower stem internodes, whereas many collected after 1970 have yellow-brown lower stem internodes. Plants from interior wetlands, presumed to be native, also have reddish-purple lower stem internodes, while those from roadsides are either yellow-brown or reddish-purple. The plants with reddish-purple lower stem internodes have longer lower glumes and longer ligules on middle leaves than the plants with yellow-brown lower stem internodes. They are thus referable to the native subsp. americanus based on morphological as well as circumstantial evidence. Lower glume length and ligule height are confirmed as valuable characters for separating subsp. australis and subsp. americanus. Basal stem internode color is a valuable character, particularly for field identification and especially when combined with morphological measurements. Basal stem internode color was also indicated to be useful for studying the history of invasion of subsp. australis in eastern Ontario, and may prove similarly useful in other parts of northeastern North America, as well.

Eupatorium paludicola (Asteraceae) is a new species from the Atlantic Coastal Plain of North and South Carolina. It resembles E. leucolepis (DC.) Torr. & A. Gray, from which it is most readily distinguished by very narrow (2–4.5 mm wide) ascending-recurved to erect-incurved leaves, and by shorter involucres, pappi, and cypselae. It inhabits isolated, herb-dominated wet depressions with variable hydrology such as clay-based Carolina bays.

Resolution of the systematic relationships of the New England Boneset, Eupatorium novae-angliae, has been elusive. This rare species, known from only 15 sites in Massachusetts and Rhode Island, has been demonstrated to be male-sterile and agamospermous, and thus inferred to be polyploid, but its progenitor diploids have not been identified clearly. In a study that hinged on a combination of fieldwork and morphological study together with molecular analysis, we have demonstrated that E. novae-angliae contains ITS repeats characteristic of two sexual diploid species of the genus. One is the widespread E. perfoliatum, the second is a previously unrecognized endemic to clay-based Carolina bay and depression meadow habitats in the Carolinas, that had been included in E. leucolepis and is now recognized as a separate species, E. paludicola. The molecular data highlight the distinctiveness of E. novae-angliae and underscore the need for efforts to continue to protect it in its native habitat.

In 1853, John L. Riddell, then a leading multidisciplinary scientist in Louisiana, validly published 34 binomials and trinomials of vascular plants from Alabama, Louisiana, and Texas. Most of these names were first published in 1852 in a checklist of Louisiana plants, but lacked descriptions and hence were not then validly published. This paper has been previously noted by several biologists. The following year, Riddell published a paper in the same journal providing brief descriptions of all of these supposedly undescribed plants. Unfortunately, this paper with the valid publication of these names has rarely been noted, as the journal is not widely available in botanical libraries. The few names so noted are often attributed to the supposed publishing author rather than to Riddell, who alone should be credited as the author for the new taxa. The genera of flowering plants in which new species or varieties are described are listed alphabetically as follows: Acalypha, Campanula, Cucumis, Dicliptera, Eriogonum, Lysimachia, Melothria, Physalis, Plantago, Polygonum, Potamogeton, Quercus, Sagittaria, and Urtica. The protologue of each of the published names is included and, for those that we could identify, synonymy is listed. For those species which we were unable to identify, we have included the protologues as a convenience to those not having access to the 1853 publication. We hope others may have the floristic or monographic knowledge to identify those names we have been unable to.

Chamaedorea glaucifolia, previously thought to be distributed in the Depresión Central de Chiapas and the adjacent Sierra Norte, is reported for the first time in southern Veracruz State in an evergreen tropical rain forest of the Uxpanapa region. It has also been found in the Sierra Madre del Sur, Chiapas, thus extending its range considerably. Chamaedorea tuerckheimii, previously known only from Guatemala and the Los Tuxtla region of Veracruz, was found in the northern mountain ranges of Chiapas and extending its range to a locality in the southern mountains of Tabasco bordering Chiapas. Notes on habitat and distribution are presented, as well as a “Critically Endangered” Red List Category (C1a) recommendation for C. tuerckheimii.

Quantitative data on structure and composition of all strata of vegetation were collected from 20 study sites in the Boston Mountains Subsection of the Ozark Mountains of northwestern Arkansas in June 2004. All study sites were located at upper slope or ridgetop positions and occurred at elevations > 457 m. Oaks (Quercus spp.) were dominants in the tree stratum (stems ≥ 10 cm DBH) for all 11 sites located < 549 m but in only one site > 590 m. In these higher elevation sites, various other species, including sugar maple (Acer saccharum), were relatively more important. Hickories (Carya spp.) were consistently present but usually achieved dominant or codominant status only at higher elevations. Dogwood (Cornus florida) and red maple (A. rubrum) were the two most important species represented in the small tree (stems ≥ 2.5 cm but < 10 cm DBH) stratum. The Ozark data set was compared with data obtained from a series of topographically similar study sites in the central Appalachian Mountains of eastern central West Virginia. For the tree stratum, the two regions shared 15 species in common, but these were usually quite different in importance. Oaks were relatively more important in the Ozarks but typically were underrepresented in the small tree, sapling, and seedling strata in both regions.