From Plant Press, Vol. 3, No. 2, April 2000.
March was a red-letter month for the local flora of the Washington-Baltimore area. On 21March, the Annotated Checklist of the Vascular Plants of the Washington-Baltimore Area. Part I. Ferns, Fern Allies, Gymnosperms, and Dicotyledons by Stanwyn G. Shetler and Sylvia Stone Orli was released. The Annotated Checklist is a complete revision of Frederick Hermann’s A Checklist of Plants in the Washington-Baltimore Area (1941, 1946) for the taxonomic groups covered. Part II will cover the monocotyledons. It is offered as a stepping-stone to a new manual of the plants of this area. The entries include common names, synonyms, indication of whether the species occurs in the District of Columbia, Maryland and/or Virginia sectors of the area, status in the flora (native or introduced), and occasional notes. The species total is 2001, with 781 (39%) being introduced.
The day after the Checklist appeared, The Washington Post carried a front-page story on the paper “Early Plant Flowering in Spring as a Response to Global Warming in the Washington, DC, Area” by Mones S. Abu-Asab, Paul M. Peterson, Shetler, and Orli (in press). This paper, based on first-flowering records of local species maintained by Shetler and colleagues since 1970, shows that in 2000 the spring-flowering plants are blooming earlier on average than they did in 1970. The 100 species with the longest records (19-29 years) were analyzed, and they bloom 2.4 days earlier than in 1970. When the 11 species (including Osmorhiza claytonii, Lonicera japonica) that actually bloom later are removed, the remaining 89 species show an advance of 4.5 days. The majority of the 100 species bloom more than 5 days earlier and some (e.g., Aquilegia canadensis, Arisaema triphyllum) bloom much earlier on average. Washington’s famed cherry blossoms, the “hook” for the Post story, are blooming about a week earlier today. These trends are all statistically significant. Furthermore, NOAA weather data over the same period show a small but significant warming trend in the area, based on minimum temperatures, and this trend correlates with the flowering data: the warmer the average minimum temperature, the earlier the average flowering. Of the more than 125 persons who have contributed to the database of first-flowering records, departmental botanists Aaron Goldberg and the late John J. Wurdack have been the biggest contributors. The present database of 650 native and naturalized, and more than 1900 cultivated spring-flowering species, was created by Sylvia Stone Orli.
More information on the “Early Flowering” newspaper article can be found at the Museum’s Website <http://www.mnh.si.edu/feature.html> and the Website for the Flora of the Washington-Baltimore Area <http://www.nmnh.si.edu/botany/projects/dcflora>. At the latter site, the databases for the Checklist and the Spring Flowering Records can be searched. The data for the article can be found at <http://www.nmnh.si.edu/botany/projects/dcflora/floweringdata.html>. [by Stanwyn G. Shetler]
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