1899] BRIEFER ARTICLES 133 
York (/. Carey); Easton, Pennsylvania (Z. C. Porter); Farmer Mt., 
Carroll co., Virginia ( John K. Smait). 
Habitally Pycnanthemum verticillatum should rarely be confused 
with either P. muticum or P. Torreyt. P. muticum has broader ovate- 
serrate leaves, the upper distinctly whitened ; the bracts of the glom- 
erules are linear or lance-attenuate ; andthe long stamensare generally 
much exserted. Though in foliage P. verticillatum is approached by 
P. muticum, var. pilosum Gray, that form is readily distinguished by its 
characteristic pubescence and bracts. 
tom the somewhat similar 7. lanceolatum, to which Bentham once 
referred it, P. verticillatum is distinguished by its broader leaves, the 
Upper ones pubescent ; by its more open inflorescence ; by the longer 
more acuminate and less pubescent bracts of the glomerule ; and by 
the sharper calyx-teeth and smaller corolla. 
Some forms of Pycnanthemum Torreyi approach P. vertictllatum, 
but usually that Species may be readily told by its thinner narrowly 
lanceolate leaves, distinctly tapering at the base, the upper mostly 
slabrous ; and y the narrower bracts of the glomerule. The stamens 
of the wo plants present a striking difference. In P. Zorreyd they are 
long-exserted, equaling the upper lip of the corolla; while in 2. vertt- 
cllatum they are 
the corolla, 
Verticillatym 
Ti orreyi 
, 
More re. ‘ 
Senus — to treat it asa species. The specific characters in the 
<a are not so fixed as would be convenient for 
co » DUt as species go in the group, P. /anceolatum 
and P, “inifolinm i P 8 Adal! 3 : 
m S€ems Ww 
™m, Camby idge, Mass. 
