106 Holm Additions to the Flora of Washington. 



have immigrated from adjacent territory. In the latter category 

 appear to be several species from the Potomac shore : Ranunculus 

 Pennsylvanicus, Flcerkea proserpinacoides, Phacelia Covillei, etc. The 

 flora of the District is, however, probably not yet thoroughly 

 known, and we need simply to recall the fact that a locality so 

 rich as that near Silver Hill thus far seems to have escaped at- 

 tention, and the river banks between Chain Bridge and Great 

 Falls are yet far from being well explored. 



It was the author's intention to give some additional notes in 

 regard to the time of flowering, as many new facts have been 

 reported ; but these have not been included in the following list, 

 because it has been found almost impossible to state with any 

 certainty the true dates for many of the species in question. 

 This is especially true of the spring flowers. In the year 1890, 

 for instance, about forty species were found in bloom as early 

 as the 15th of January, but in 1892 only a few were observed 

 before the end of March. 



It has been thought best to follow the nomenclature and 

 arrangement of Professor Ward's Flora. 



It is intended to continue the publication of lists of additions, 

 and the botanists of Washington are requested to send to the 

 author their notes upon species new to .the District and upon 

 new localities for rare plants. 



RANUNCULACEJE. 

 3. Clematis Virginiana L. 



Anacostia road and Mill road, flowering in the first week of 

 August. H. W. Henshaw. 



*20a. Ranunculus Pennsylvanicus L. 



On the Virginia shore of the Potomac, just above Aqueduct 

 Bridge ; collected with flowers a.nd fruit in the third week of 

 August. The author. 



*22a. Caltha palustris L. 



Flowering specimens brought to Center Market were said to 

 have been collected in Anacostia River marsh at Bennings 

 Bridge and three "miles north of Bladensburg. The specimens 

 referred to in Mr. Knowlton's list as collected in Rock Creek be- 

 long not to this species, but to Ranunculus Ficaria L. It is very 



