Introduction 



number of new species of plants, several of which were named in 

 his honor. 



In 1896 Canby suggested the formation of the "Edward Tatnall 

 Herbarium of New Castle County Plants." This plan has been 

 carried out by segregating in separate cases all of the local speci- 

 mens from the Canby Herbarium of the Society of Natural History 

 of Delaware. 



John T. Pennypacker (1838-1926), a member of the Academy of 

 Natural Sciences of Philadelphia, and for many years treasurer of 

 the Society of Natural History of Delaware, contributed a series of 

 local plants to the Tatnall Herbarium. 



Rev. John P. Otis (1846-1934) made a considerable collection 

 of plants of the Peninsula, chiefly from the vicinity of Wilmington, 

 from Sussex County, Delaware, and from Cecil and Wicomico 

 Counties, Maryland. The bulk of his herbarium is in Philadelphia, 

 at the Academy of Natural Sciences, but many sheets are preserved 

 in the Edward Tatnall Herbarium in Wilmington. 



The Philadelphia Botanical Club, affihated with the Academy 

 of Natural Sciences, was founded in 1891, and adopted as its working 

 range all counties within fifty miles of Philadelphia. This included 

 the northernmost parts of Delaware and Maryland, and several 

 members of the new Club soon organized expeditions into New 

 Castle and Cecil Counties, and some of the more active extended 

 their operations into lower Delaware. Most of the specimens 

 collected on these trips are now at the Academy of Natural Sciences 

 and the University of Pennsylvania. A noteworthy undertaking was 

 the so-called "Symposium of 1909," led by C. S. Wilhamson, and 

 participated in by several members of the Club. From July 4th to 

 9th a considerable part of Sussex County was explored, and many 

 specimens obtained. An account of this expedition was published 

 by Williamson in Torreya 9, 160-166 (1909). 



The Annotated List. The Society of Natural History of Dela- 

 ware now accepts as its special field the entire peninsula of Dela- 

 ware, Maryland and Virginia, instead of limiting it to the state of 

 Delaware, as originally intended. Pursuant to this poUcy, the 

 writer was asked to prepare a list of the known flora of the Penin- 

 sula, and the work was begun in the spring of 1928. The Society 

 provided the necessary equipment for mounting the specimens to 

 be collected, and for a card catalog of the species. 



Data for the list came from several sources. The contents of 



xix 



