30 



FLORA OF WASHINGTON AND VICINITY. 



Sisymbrium Alliaria April 7, 1878 



Viola cucullata April 7, 1878 



Viola striata April 7, 1878 



Viola glabella April 7, 1878 



louidium concolor April 7, 1878 



Sileue Pennsylvanica April 7, 1878 



Cerastium valgatum Ajiril 7, 1878 



Cerastium oblougifolium April 7, 1878 



Geranium maculatum April 7, 1878 



Oxalis corniculata var. stricta Ajiril 7, 1878 



Cercis Canadensis Aj^ril 7, 1878 



Poteutilla Canadensis Ai^ril 7, 1878 



Thaspium trifoliatum April 7, 1878 



Cornus florida April 7, 1878 



Chrysogonum Virginianum April 7, 1878 



Senecio aureus April 7, 1878 



Fraxiuus viridis April 7, 1878 



Phlox divaricata April 7, 1878 



Lithospermum arvense April 7, 1878 



Betula nigra April 7, 1878 



Populus monilifera April 7, 1878 



Arissema tripbyllum April 7, 1878 



Erytbronium albidum April 7, 1878 



Trillium sessile — April 7, 1878 



My special observations on the vernal flowering time of plants extend 

 about two weeks later, or to the end of the third week in April, after 

 which the gTeat number of plants in bloom, including the amentaceous 

 trees, render it diflicult to i)ursue the investigation, while at the same 

 time the facts become less valuable. The results for the second and 

 third weeks of April, always excluding all previously enumerated, are 

 as follows : 



Arabis lyrata Aj)ril 9, 1876 



Fraxinus pubescens April 11, 1880 



Salix cordata April 11, 1880 



Salix i)urpurea April 11, 1880 



Vaccinium corymbosum April 12, 1874 



Carex platyphylla April 12, 1874 



Poa annua April 12, 1874 



Thalictrum dioicum April 14, 1876 



