20 Rhodora [JANUARY 
with the Pacific coast S. microcarpus, and in the Illustrated Flora the 
same name is given it. That the northeastern species, passing as "A. 
microcarpus,” is clearly distinct from S. sy/vaticus, there can be no 
doubt. The latter is a coarser plant, with conspicuously broader leaves 
and more ample inflorescence. The spikelets are rarely more than six 
or eight in a glomerule (generally fewer), and the rays of the umbel 
are ordinarily much more elongated. It has a uniformly 3-parted 
style and three stamens and usually six bristles, and the larger achene 
is darker colored and with a distinct ridge or angle on the back. This 
plant, the true S. sy/vadicus, is of decidedly more southern range than 
the other, barely reaching southern Maine and New Hampshire, and 
from there extending southward to the Carolinas. In its flowering 
season, too, as shown by the dates on eighty herbarium labels of the 
two species, it is about “iree weeks later than the more slender northern 
plant. 
Although the slender northeastern plant agrees with the northwestern 
and Pacific coast S. microcarpus in having 2-cleft styles and four bris- 
tles, and whitish barely angled achenes, there is little else to suggest 
their identity. The true S. microcarpus is as coarse a plant as the 
eastern and European A. sy/vaticus. Its leaves are broad and its 
inflorescence ample, with long often flexuous rays. ‘The spikelets are 
solitary or in glomerules of from 2 to 8. The upper sheaths of the 
plant in all the specimens examined are green or very slightly reddish 
tinged, and it is stated by those who know the plant in the field that 
in fresh plants there is no striking color in the upper sheaths. The 
more slender eastern plant, on the other hand, is quickly recognized 
by the deep purplish-red band at the base of each sheath, although 
this same color is occasionally seen in the otherwise dissimilar A. 
sylvaticus. 
The northeastern species, from the apparent constancy of this 
marking, may be called 
S. rubrotinctus. Stem slender or rather stout, 4 to 9 dm. high: 
leaves smooth, 4 to 13 mm. wide, the upper equalling or slightly ex- 
ceeding the umbel; the sheaths conspicuously colored with red or 
purplish brown ; involucral leaves mostly 3, the longest sometimes ex- 
ceeding the umbel: rays of the umbel numerous, the 3 to 5 longest 
ones o.5 to r.5 dm. long, stiff, ascending, subequal, the many shorter 
ones ascending or spreading; the branchlets and ultimate branchlets 
of the inflorescence stiff, not flexuous: spikelets 4 to 6 mm. long, 
ovate-oblong to cylindric, in glomerules of from 3 to many; scales 
