78 FLORA OF WASHINGTON AND VICINITY. 



tPotentilla Norvegica, L. 



August or September. 



tPotentilla Canadensis, L. Cinque-Foil. Five-Finger. 

 April. 



tPotentilla Canadensis, L., var. simplex, Torr. & Gray. 

 May. 



Alchemilla a}rensis, Scop. Lady's Mantle. 



Ouly once found, on Meridian Hill, by Dr. Vasey and Professor Chickeriug. Long 

 since obliterated. 



tAgrimonia Eupatoria, L. Commox Agrimony. 

 July or August. 



t Agrimonia parviflora, Hook. Small-flowkred Agrimony. 

 August or September. 



tPoterium Canadense, Bentb. & Hook. Canadian Burnet. 



Tbird week in September. 



Poterium Sanguisorba, L. Bl'RNET. 



Odentou, Md., May 30, 1877. Should be looked for nearer. 



Rosa setigera, Michx. Climbing Rose. 

 Escajied in some places. June. 



Rosa Carolina, L. Swamp Rose. 

 June. 



Rosa lucida, Ebrli. Dwarf Wild Rose. 

 End of May. 



t Rosa rubighiosa, L. Sweet-Brier. 

 June. 



Rosa micrantha, Smith. Smaller-flowered Sweet-Brier. 

 June. 



Rosa cat) ilia, L. DoG-RosE. 

 High Island. 



tPirus coronaria, L. American Crab-Apple. 



Northwest Branch (Professor 'Chickering) ; a few trees ouly. End of April or 

 tirst of May. 



+ Pirus arbutifolia, L. Choke-Berry. 



Two forms, a high and a low bush, the former of which flowers two weeks later 

 than the latter, grows in very moist swamps, and bears much smaller berries, which 

 persist throughout the winter. End of April (low-bush) to middle of May (high- 

 bush). 



tPirus arbutifolia, L., var. melanocarpa, Hook. 



North of Bladeusburg. Fruit collected July 20, 1879. 



Cratcegus cordata, Ait. Washington Thorn. 



Rock Creek Church Road near Soldiers' Home, also Bladensburg. Not common. 

 Second week in June ; fruit in October, 



