PHILOSOPHICAL SOCIETY OF "WASHINGTON. 65 



treatise on the flora of this vicinity, and for a new and revised cat' 

 alogue of the plants. While there now exists a provisional cata- 

 logue containing most of the species which have been collected or 

 observed by botanists during the past six or seven years, it consists 

 of so many small annual accretions, due to constant new discoveries, 

 and contains withal so many blemishes and imperfections, incident 

 to its hasty compilation and irregular growth, that it has ceased, in 

 great part, to meet the demands of the present time. The elabora- 

 tion of a systematic catalogue of the local flora was not, however, 

 at the outset at all contemplated, but merely the presentation of 

 certain notes and special observations on particular species, which 

 had been made in the course of some nine years of pretty close at- 

 tention to the vegetation, and somewhat varied and exhaustive field 

 studies in this locality. 



The flowering-time of most species here is much earlier than 

 that given in the manuals, and is, moreover, in many cases, very 

 peculiar and anomalous, rendering it important to collectors as well 

 as interesting to botanists to have it definitely stated for a large 

 proportion of the plants. It being thus necessary to extend the 

 enumeration so far, it was thought that the remainder might as well 

 be added, thus rendering it a complete catalogue of all the vascular 

 plants known to occur here at the present time. To these has been 

 appended the list of musci and hepaticce prepared by the late Mr. 

 Rudolph Oldberg for the Flora Columbiana, which has been left un- 

 changed except in so far as was required to make it conform strictly 

 to Sullivant's work which has long been the standard for this 

 country. Dr. E. Foreman has also furnished the names of a few 

 of the Characece collected by himself, and named by Prof. Farlow, 

 of Cambridge, which, in the present unsettled state of the classifi- 

 cation of the cryptogams, have, for convenience, been placed at the 

 foot of the series. 



In undertaking this compilation I have endeavored to resist the 

 usual temptation of catalogue makers to expand their lists beyond 

 the proportions which are strictly warranted by the concrete facts 

 as revealed by specimens actually collected or species authentically 

 observed ; but have been content to set down only such as I can 

 either personally vouch for, or as are vouched for by others who 

 have something more substantial than memory to rely upon ; pre- 

 ferring that a few species actually occuring but not yet seen should 

 be omitted and afterwards supplied, rather than that others, sup- 

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