262 PITTONIA. 
stouter awns of more than half the length of the achene and 
slenderly retrorse aculeolate, the third awn, always present, 
two-thirds as long as the others. 
On wet banks, in Jackson Co., Missouri, 30 Oct. 1893, B. 
F. Bush, n. 164. The species remarkable as combining 
almost the aspect of a dwarf simple-leaved B. frondosa, with 
the character of the B. cernua group astotheachenes. The 
heads, as seen in the dry, are not obviously nodding; but 
that they were so when living is evinced by the fact that 
Mr. Bush, who collected the specimens, distributed them for 
those of rayless B. cernua. 
Y B. mARGINATA. Low and decumbent, branched from the 
base, 3 to 6 inches high, glabrous below, sparsely rough-pu- 
bescent above: leaves almost linear, 1 to 2 inches long, ses- 
sile but not connate, widely spreading, slightly serrate- 
toothed: heads many, short-peduneled, strongly cernuous, 
large for the plant, hemispherical; outer bracts exceeding 
the inner, oblong-linear, entire; inner dark-brown by many 
closely eontiguous dark lines, but with conspicuous bright- 
yellow margins: rays few and small: disk-corollas ‘with 
tube and limb about equal: achenes smooth, shining and of 
a dark red-purple, compressed-quadrangular, none of the 
angles corky or in any wise thiekened, the two principal 
ones delicately retrorse-aculeolate; awns 4, nearly equal, 
slender, yellow, delicately aculeolate. 
Near Salmon, Idaho, 31 Aug., 1895, L. F. Henderson (n. 
3,855), distributed for B. cernua, and indeed very strictly of 
this group, though with beautiful specific characters. 
6. Segregates of BIDENS CHRYSANTHEMOIDES, Michx. 
This name, together with its synomym B. levis, ill-advis- 
edly made some years ago, embraces a considerable diversity 
