Little is known about the single reported population of Dirca mexicana. I monitored air temperature from mid-2005 through mid-2007, analyzed pH of soil, used the global positioning system (GPS) to define geographical boundaries of the population, explored for additional populations, and studied aspects of sexual and asexual reproduction in situ and among seedlings in greenhouses. Temperature ranged from −2 to 35.5°C, and weekly means were 7.4 to 18.1°C. Soil pH was 6.3. No other populations were found at sites nearby with similar slopes and aspects, but a second distinct cluster of plants was found 221 m from the portion of the known population described previously. Numerous individuals of Catasticta nimbice nimbice, a butterfly in the family Pieridae, visited flowers in mid-March, 2007. Drupes were observed in May four of five years, and drupe count per plant was 3 to 131 among individuals with basal trunk diameters of 10 to 46 mm in 2007. Genetic analysis of 45 individuals revealed no putative clones. Drupes of D. mexicana were longer and wider than those of the other two species in the genus, while size of seeds was intermediate. Seedlings isolated from pollinators in a greenhouse flowered for the first time and formed viable seeds during their fourth spring of development, demonstrating the capacity of D. mexicana to self-pollinate or to form seeds via apomixis. These observations improve our understanding of the habitat and reproductive biology of this endemic species.

Amelanchier alnifolia var. pumila (Smooth Saskatoon, Dwarf Serviceberry) is reported as new to Canada from the Crowsnest Pass and Castle Mountain regions of the Rocky Mountains of southwestern Alberta. It occurs in open prairie habitat in cool montane parklands. Completely glabrous with prominently toothed leaves, and with a discrete distribution including the Rocky Mountains and adjacent plains, A. alnifolia var. pumila is a distinctive taxon worthy of recognition. At the Canadian sites it occurs with A. alnifolia var. alnifolia and a range of putative hybrids. The Canadian collections are described, and compare well with the type material. A key to the Amelanchier taxa of Alberta and British Columbia is included.

Several nomenclatural changes have taken place in Platanthera within the past decade, including the recircumscription of species and newly described segregate taxa. Collections in herbaria should be updated to reflect these changes, however Platanthera herbarium specimens are difficult to identify because diagnostic qualitative and quantitative characters present in the field are not always available in dried material. Such a problem is found in P. hyperborea s. lat. from continental North America, which is now known to comprise the diploid P. aquilonis and the putative allotetraploid P. huronensis. Platanthera aquilonis and P. dilatata are commonly regarded as progenitors of P. huronensis. Platanthera hyperborea s. str. is not known to occur in continental North America. I undertook a study to determine if herbarium specimens of P. hyperborea s. lat. and the closely related P. dilatata representing British Columbia populations could be annotated to reflect the current taxonomic treatment. I placed P. hyperborea s. lat. and P. dilatata herbarium specimens into groups using keys and descriptions provided in recent treatments. Principal components analysis (PCA) and ANOVAs were used to determine if groups existed in the data set. The univariate statistics supported the presence of three groups in the data set and individuals of known ploidy helped to confirm that phenetic clusters on the PCA scatterplot corresponded to the appropriate species. Using techniques outlined in this paper, Platanthera herbarium specimens can be annotated to reflect current taxonomic treatments.

Rapid assessment surveys of fouling seaweed populations were conducted at 67 sites between Downeast Maine and Staten Island, New York during August of 2000, 2003, and 2005, plus July–August of 2007. A total of 126 taxa were recorded, including 29 Chlorophyceae, 31 Phaeophyceae, 55 Rhodophyceae, four Cyanophyceae, one Xanthophyceae, and six macroscopic colonial diatoms (Bacillariophyceae). Several species were fast-growing nuisance organisms (e.g., Ulva spp.), while seven were introduced taxa. Four introduced species originated from Asia either directly or secondarily (Codium fragile subsp. fragile, Grateloupia turuturu, Neosiphonia harveyi, and Bonnemaisonia hamifera), two were from Europe (Lomentaria clavellosa and L. orcadensis), and one from the North Pacific (Melanosiphon intestinalis). Neosiphonia harveyi was the most widely distributed introduced taxon, occurring at 48 sites (71.6%), while L. clavellosa and L. orcadensis were only found at 3 sites (4.5%). Repeated observations (i.e., 2000, 2003, and 2007) at three sites in Massachusetts documented a recent rapid expansion of the invasive red alga G. turuturu into the Gulf of Maine through the Cape Cod Canal. The numbers of taxa per site were highest between Maine and Massachusetts (28–42 taxa) and lowest (1–13 taxa) in southern New England and New York, presumably because of increased loading of various pollutants within Long Island Sound and near New York City. The highest mean (± SD) number of taxa per state was recorded in New Hampshire (28.8 ± 8.0) and the lowest in Rhode Island (7.1 ± 3.6). The green and red algae exhibited peak numbers in New Hampshire (i.e. 9.0 ± 3.1 and 11.6 ± 5.1), while brown algae were maximal in New Hampshire (8.2 ± 1.1) and Maine (7.8 ± 3.4) and much lower in Connecticut (1.0 ± 1), Rhode Island (1.1 ± 2.9), and New York (1.2 ± 1.0). Fifty-four species were limited to 1–3 sites (1.5–4.7%), while only 7 occurred at > 50% of the sites. The most ubiquitous seaweeds included three opportunistic green algae (U. intestinalis, U. lactuca, and Blidingia minima), two perennial browns (Fucus vesiculosus and Ascophyllum nodosum), and the introduced Asiatic red alga, N. harveyi. Thirty-six taxa were restricted to individual states (31.3%), with Massachusetts exhibiting the highest number of unique taxa (17 or 14.8%) and Connecticut and New York the lowest (one taxon each or 0.9%). Massachusetts also had the highest number of total and mean shared species (86 and 43.3 ± 10.7, respectively), while Connecticut had the opposite pattern (18 total and 15.0 ± 7.5 shared taxa). Cheney's floristic ratio indicated that seaweeds restricted to the north of the Cape Cod Canal formed a cold-water flora, while those limited to the south of the Canal were somewhat less boreal. Most taxa from each state were annuals and exhibited cosmopolitan local distributional patterns, occurring in both open coastal and estuarine sites.