St. Lawrence Island, in the northern Bering Sea, is an important biogeographic link between the flora of northeastern Asia and northwestern North America. A vascular plant inventory was conducted on St. Lawrence Island in the 1960s by Steven Young in which 250 taxa were documented. Since that time, very few collections have been made on the island. We conducted a vascular plant survey to improve our understanding of baseline floristics and identify populations of species of conservation concern. Of the 166 taxa we collected in late July 2012, a number of collections represent new or significant finds. Eritrichium villosum, a Siberian taxon not previously recognized from North America, was collected on north-central St. Lawrence Island. This taxon, however, had been collected under a different name by Young in the late 1960s. Iris setosa subsp. setosa is a new record for the island. Iris setosa, although common along the eastern Bering Sea coast from Kotzebue Sound south through the Aleutians, appears to be very restricted on St. Lawrence Island and has only been noted by residents in recent years. Erigeron humilis and Moehringia lateriflora are also new records for the island. New populations were located of the globally rare species: Cardamine blaisdellii, Claytonia arctica, Micranthes nudicaulis subsp. nudicaulis, Papaver gorodkovii, Potentilla fragiformis, Ranunculus camissonis, and R. turneri subsp. turneri. We have included an annotated species list of 281 taxa, illustrated under-sampled regions of the island, and described the biogeographic affinities of the flora to other high latitude regions. The island's flora has strong biogeographic affinities to eastern Beringia (Alaska and western Yukon), particularly to the Seward Peninsula and less strongly to the Russian Far East. Numerous circumpolar arctic and alpine species were also present, with a minority of East-Asian species known from very few populations in extreme western Alaska.

Nine Element Occurrences (EOs) of Appalachian Jacob's-ladder Polemonium van-bruntiae in Vermont were recognized in 2002. Presently there are 15 EOs comprising 79 Sub-Element Occurrences (subEOs). The author monitored all 79 subEOs at least once and 31 of them twice between 2004 and 2017. The total number of sexually reproductive stems was 32,300, averaging 2153 per EO and 409 per subEO. Six subEOs had fewer than 10 plants each. More than half the subEOs occurred in wooded seeps; the remainder occurred in wet meadows, alder thickets, northern white cedar swamps or human-altered patchy habitats that mimic seeps. In Vermont the species is currently known only from southeast Addison County. The species is now more populous but only slightly more widely distributed in Vermont than in Deller's account. Increase in numbers is due to discovery of new EOs and subEOs, as well as to population growth of the EOs known since 2002. It remains at risk to the same variety of threats that it was believed subject to in 2002.

Carex arizonica M. Licher, G. Rink, and A. A. Reznicek (Cyperaceae) is a new species of riparian sedge in Arizona, USA and apparently Chihuahua, Mexico. Previously, these plants were determined variously as Carex meadii, C. aurea, or C. hassei. Carex meadii, reported from Arizona based on this entity, is now not known within Arizona. With mostly three stigmas, Carex arizonica would seem to be most closely related to C. klamathensis, a serpentine endemic in southwestern Oregon and northwestern California, which belongs to section Paniceae. However, the widespread Carex aurea of section Bicolores, which usually has flowers with two stigmas, may have played a role in the origins of C. arizonica.

Sibbaldia procumbens (Rosaceae) is globally widespread in alpine and subalpine habitats of the Northern Hemisphere, where it thrives in areas of late-lying snow that persist into summer. Despite its widespread circumboreal distribution and local abundance, Sibbaldia is one of the rarest plants in New England, USA, occurring only in a single ravine on Mount Washington, New Hampshire. The New Hampshire population has evidently been declining for several decades, possibly the result of a combination of interspecific competition, over-collection, and changes in environmental conditions. We assessed historical trends, current status, and potential causes of decline of the New Hampshire population through evaluation of herbarium and historical records, field surveys, and photographic comparisons. Our research at seven New England herbaria revealed 236 plants with roots, including many large adult plants, on 65 herbarium sheets. Most of these plants were collected between 1846 and 1908, representing trophy collection activity characteristic of some novel species during that period, and which may have had a lasting impact on the reproductive capacity of this long-lived perennial. Contemporary surveys (within the last 40 years) establish a continuous decline in abundance over time. During timed surveys at two previously documented stations within Tuckerman Ravine and adjacent appropriate habitat, we found no evidence of the species. We observed encroachment of the local snowbank habitat by mountain alder [Alnus viridis (Chaix) DC. subsp. crispa (Aiton) Turrill], and possibly other species. Our observations support the hypothesis that a combination of over-collection, competition from robust vegetation, and local disturbance may have contributed to its decline and possible extirpation. If extirpated, Sibbaldia would be the first documented alpine vascular plant to be extirpated from New England. Because the decline of this species may have been anthropogenically facilitated, we recommend that the feasibility of re-establishment (from Mount Washington source material) be evaluated.