50 MISSOURI BOTANICAL GARDEN. 
hastately lobed leaves. In all these conditions there is 
much variation in form and size of achenium, stamen 
length, and in the size of the fruiting head. They occur 
together throughout the range and seem to be the result 
of different habitat, rather than to mark distinct forms or 
varieties. 
Specimens examined from Vermont (Pringle, 1879; Faxon, 1882; 
Morong, 1885); New York (Dr. Pitcher, 1829; Sartwell, Penn Yan; 
Ward, 1879; Clinton, in the rapids above Goat Island, Niagara; Engel- 
mann, 1840, 1856; Robbins, 1866; A. Gray); Connecticut (Wright) ; 
Pennsylvania (Porter; Guttenberg, 1879; James, 1860; Britton, 1889) ; 
New Jersey (James, 1848; Porter, 1860; Morong, 1891; Beyrich); Dela- 
ware (Tatnall, 1860); Ohio (Riehl, 1835, 1836; Engelmann; Riddell, 
1868; Werner, 1887); Kentucky (Rafinesque); Tennessee (Gattinger, 
1883); Illinois (Riehl, 1846; Engelmann, many dates and localities; 
Brendel, 1873; Eggert, 1877; Hitchcock, 1891; Bush, 1892); Iowa 
(Hitchcock, 1888); Nebraska (Williams, 1890; Smith, 1890; Rydberg, 
1891; Bates, 1891, 1893, Sand Hills); Minnesota (Sandberg, 1885, 1890, 
624 and 638, 1891; Herrick, 1878; Bailey, 542, 1886; Ballard, 273, 588, 814, 
1891; Sheldon, 321, 1891, and 3149, 3211, 1892); Wisconsin (Houghton, 
1831; Robbins, 1866) ; Michigan (Bigelow, 1865) ; Ontario (Macoun, 1868, 
1884); Canada (Pursh). 
+ + + Achenium obovate, with a short lateral beak; filament dilated 
at the base, pubescent; bracts connate, glabrous. 
S. graminea Michx. Fl. Bor. Am. 2: 190 (1803). S. acuti- 
folia Pursh, Fl. Amer. Sept. 397 (1814). WS. simplex 
Torr. Comp. 356 (1826), not Pursh. S. sagittifolia 
var. simplex Hook. Fl. Bor. Amer. 2: 167 (1840). 
S. Purshii Kunth, Enum. 8: 160 (1841). SS. stoloni- 
fera Engelm. and Gray, Boston Journ. Nat. Hist. 5: 
234 (1847). 
Monoecious or dioecious, 1 to 6 dm. high; leaves lanceo- 
late to ovate elliptical, acute at both ends; or very rarely 
truncate or hastate with short divaricate lobes at the base, 
1 to 6 cm. wide, 5 to 15 em. long, 3-to 5-nerved, the 
nerves free to the base; scape simple, slender, erect, with 
few remote, or many verticils sometimes approximate ; 
bracts ovate, acute, 3 to 5 mm. long, connate to the middle ; 
fertile and sterile pedicels about equal, spreading, 1 to 3 cm. 
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