70 FLORA OF WASHINGTON AND VICINITY. 



^Hypericum proUficum, L. Shrubby St. John's-wort. 



Middle of July. 

 +Hypericum perforatum, L. Common St. John's-wort. 



First week in July. Rmiuers best secured in November, 

 .f Hypericum corymbosum, Muhl. 



First half of July. 

 + Hypericum mutilum, L. 



August to October. 

 t Hypericum Canadense, L. 



August to October. 

 t Hypericum Sarothra, Michx. Orange-Grass. 



September. 



i-Elodes Virginica, Nutt. Marsh St. John's-wort. 

 July 15 to August 10. 



MALVACEiE. 



Mallow Family. 



tMalva rotundifolia, L. Common Mallow. 



May to October. • 



Malva sylvestris, L. High Mallow. 



Georgetown, near end of Aqueduct Bridge. Early in July. 



tSida spinosa, L. 



Last half of July. 



t Abutilon Avicennce, Gaertn. Velvet-Leaf 

 August. 



t Hibiscus Moscheutos, L. Swamp Rose-Mallow. 

 Late iu July. 



tEtLbiscus militaris, Cav. Halberd-leaved Rose-Mallow. 

 End of July or in August. 



Hibiscus Triomim, L. Bladder-Ketmia. Flower-of-an-hour. 

 Rare. End of August. 



TILIACEiE. 



Linden Family. 



i Tilia Americana, L. American Linden. Basswood. 

 Usually growing close to the wiiter. 



LINACEiE. 

 Flax Family. 

 H^Linum Virginianum, L. Wild Flax. 



Juno 10 to July 10. There are two well-marked forms of this species, the one 

 growing in ojjcn ground, the other in shady woods. The first of these forma beara 

 many thickly-crowded, erect, oppressed, linear leaves, 2°"" to 3™"" wide; the second 

 •bears few spreading, lanceolate leaves 4'"'" 1o (>""" in width. In the former the stem 

 is always erect and rigid, while in the latter it usually bends over and is weak and 

 .flaccid. These two forms are very noticeably distinct in aspect. 



