OPEN WOODS 345 



nearly sessile, clustered thickly in the axils ; those nearest the 

 flowers whitish, with a soft down. Time, July, August. 



There are several species of mountain-mint, found oftener 

 below the hills than upon them. Most of them have small 

 flowers with a 5-toothed calyx and 2-Iipped corolla crowded in 

 button-like heads, downy, whorled around the stem and termi- 

 nal in close cymes. With the heads are short, stiff, pointed 

 bracts. It is not easy always to distinguish the species. 



85 



P. linifblium often grows with P. lanceoldtum. It has nar- 

 rower leaves, and narrow, awn-pointed calyx teeth. Heads 

 of flowers less downy. Range of both, throughout the At- 

 lantic coast. 



86 



P. miiticum has broader leaves, with rounded or heart-shaped 

 bases and fewer and larger heads of purplish flowers in close, 

 dense heads, downy, as are also the floral leaves. 



87 



P. Thrreyi is green and not hoary, with flowers terminal in 

 heads and corymbs. 



88 



P. inccLnum has ovate, somewhat toothed, very white, woolly 

 leaves, the upper ones white on both sides. Flowers in flat 

 clusters. 



All these species grow generally in dry soil from New England 

 southward and westward. 



8g. Sessile-leaved Water-horehound 



Lycopus sessilifolius. — Family, Mint. Color, white. Leaves, 

 sessile, sometimes clasping, ovate to lance-shaped, sparingly 

 toothed, I to 2 inches long. Time, summer. 



