Despite nearly a century of research, the systematic relationships among North American pitcher plants in the genus Sarracenia (Sarraceniaceae) remain unresolved. In this study we analyzed pollen morphology of the 11 currently recognized species of Sarracenia and examined how variations in key pollen characteristics relate to our current understanding of the taxonomy of this genus. We used principal components analysis to explore variations in pollen grain size (equatorial diameter and length) and shape (number of colpi) among Sarracenia species, and used cluster analysis to compare systematic groupings of Sarracenia based on floral, vegetative, and pollen characters. We compared these results with a previously published phylogeny based on molecular data. Groupings based on pollen characteristics alone did not align completely with those based on molecular or all morphological data. In clusters based on pollen alone and those using all morphological characters, S. purpurea and S. rosea formed a single group, and S. flava, S. alata, and S. leucophylla grouped together consistently. The pollen morphology of S. jonesii and S. alabamensis differed substantially from that of S. rubra, supporting the current systematic treatment of the genus that recognizes these three taxa as distinct species.

Geranium dodecatheoides P.J. Alexander & Aedo (Geraniaceae), a new species from the Sierra Blanca in Lincoln Co., New Mexico, is described and illustrated. This new species is related to North American species of sect. Caespitosa R. Knuth, which have dichasial inflorescences and petals that are hairy on the adaxial surface. It is distinguished from other members of Caespitosa primarily by having narrow, reflexed petals.

We conducted a preliminary floristic study of six vernal pools in Acadia National Park on Mount Desert Island, Maine. Plant species were recorded on three sampling dates from April to October, 2008. Sixty-five vascular plant species from 26 families were recorded. Of these, 27 are considered occasional or uncommon in Acadia National Park. Thirteen species are new reports for vernal pools in the northeastern United States. This represents the first published study of the vernal pool flora of Acadia National Park.

In taxa with few diagnostic characters, highly variable populations pose a major challenge to delimiting species. This is especially true in Dodecatheon (Primulaceae), which has a notoriously complex taxonomic history. Previous biosystematic studies of Dodecatheon in southern Illinois support the recognition of two species: D. frenchii, a diploid sandstone cliff endemic, and D. meadia, a widespread tetraploid. However, only one morphological character distinguishes them and some experimental evidence suggests that this character may be environmentally induced. Furthermore, authors have disagreed about the nature of morphologically intergrading populations. In this study, we document patterns of variation for fruit and seed characters among populations in southern Illinois, including one atypical, morphologically intergrading population. Different seed shapes help distinguish these taxa, both in southern Illinois and across their larger ranges. We also show that the intergrading population is significantly more variable than others, and describe the occurrence of such populations in other regions where these two taxa co-occur. These two results suggest that localized hybridization between these species may contribute to their complex taxonomic history.

The seaweed flora of Bras d'Or Lake, Cape Breton Island, Nova Scotia is compared with those of the Baltic Sea in northern Europe and five Northwest Atlantic embayments ranging from Pomquet Harbour, Nova Scotia to Narragansett Bay, Rhode Island. Both Bras d'Or Lake and the Baltic Sea have experienced extensive geological and hydrographic changes during the past 15,000 years, which have resulted in limited connections to the open sea, negligible tides, low salinities, and reduced floras. The ecology of these two unique saltwater bodies differs from true estuaries like the York River of Maine, the Great Bay Estuary System of New Hampshire/Maine, and the Merrimack River of Massachusetts, which experience extreme hydrographic and tidal variability. Of the 309 total seaweed taxa recorded from the six Northwest Atlantic embayments, Bras d'Or Lake had the lowest number of red, brown, and green algae (i.e., 83) and shared taxa (mean 61.2 ± 4.9 SE), whereas Narragansett Bay had the highest numbers of total (203) and shared taxa (mean 111.6 ± 20.1 SE). Several taxa were restricted to single embayments, with a few glacial and limnic relicts occurring in Bras d'Or Lake and the Baltic Sea. Nine disjunct warm-water taxa were present in Bras d'Or Lake, with this representing the second highest numbers found in four embayments located north of Cape Cod, Massachusetts; this pattern reflects the characteristics of a shallow inland lake. Eleven introduced taxa were recorded from the various Northwest Atlantic embayments, ranging from two in Bras d'Or Lake to 3–10 in the other five embayments. The absence of an intertidal fucoid zone in the Lake (and the Baltic Sea) is probably associated with several physical factors, including a lack of tides, extensive ice-scouring, long-lasting atmospheric reductions of sea level, and reduced salinities. By contrast, the occurrence of subtidal fucoid algae within both brackish water habitats is probably due to a lack of strong competition from perennial kelp populations, which have limited tolerances to low salinities. Morphological features of attached submerged fucoids are analogous to those of loose-lying or entangled salt marsh forms, which are usually small, thin, profusely branched, and have extensive vegetative fragmentation. Unique aegagropilous (detached, ball-shaped) populations of Gracilaria tikvahiae also were found at some inland Bras d'Or Lake sites, presumably resulting from ice scouring and detachment.