The Ohio Naturalist. 
[Vol. V, No. 6, 
318 
their characteristic elliptical shape and tapering base easily dis- 
tinguish it from that species and warrant its elevation to s])ecific 
rank. 
4. Bidens connaia Muhl. Stem erect, branching above, 4-10 
dm. high. Leaves lanceolate, sharply serrate, long acuminate at 
base and a]>ex. Heads numerous, aljout 0 mm. high, rays none; 
outer bracts of the involucre about 5, 1-1.5 times as long as the 
disk, lanceolate-oblong, entire or minutely toothed; corollas 
5-lobed; achenes cuneate, 5 mm. long, awns 2 mm. long, 
retrorsely Ijarbed. 
There is but one specimen in the State Herbarium, from 
Wyandot County. 
5. Bidens comosa (Gray) Wiegand. Stem diffusely branch- 
ing from the base, or with short branches above, 2-7 dm. high. 
Leaves elliptic, lanceolate, or narrowly ovate-lanceolate, coarsely 
toothed, acute or acuminate, tapering at the base into a winged 
petiole. Heads usually numerous, about 1 cm. high in flow'er, in 
fruit becoming 2 cm. high and 3 cm. in diameter, outer bracts 
()-8, oblong to oblanceolate, foliaceous, serrate, twice as long as 
the disk or longer and reaching a length of 8 cm. ; corollas 
4- lobed ; achenes 7-10 mm. long, awns three, the longest 4-G mm. 
Al)undant in wet places, probably throughout. 
(), Bidens discoidea (T. & G.) Britton. Stem freely branched, 
5- 15 dm. high. Leaves 3-divided, on slender petioles, leaflets 
lanceolate or narrowly ovate-lanceolate, sharply serrate, acute 
at the base, long acuminate at the apex. Heads numerous, 5 
mm. high in flower, outer bracts 4, narrowly spatulate, exceed- 
ing the disk; achenes cuneate, about 5 mm. long, the two awns 
about 2 mm. in length. 
One specimen from Cedar Point, Erie County. 
7. Bidens frondosa L. Sparingly branched with spreading 
branches, (5-10 dm. high. Leaves 3-divided, usually thin, on 
slender petioles 3-5 cm. long, leaflets ovate-lanceolate, acute or 
rounded at the base, acute or short-acuminate at the a]>ex, 5-8 
cm. long. Heads relatively few, 5 mm. high in flower, much 
larger in fruit, outer bracts (5-8, narrowly spatulate, conspic- 
uously exceeding the disk, naked or sparingly ciliate at the base; 
achenes oblong or cuneate, dark brown to black, (5-8 mm. long, 
awns two, 4 mm. long. 
The three specimens in the State Herbarium, from Holmes, 
Meigs and Vinton counties, have]been confused with Bidens 
discoidea. The{two speciesyare at once separated by the more 
numerous outer bracts and the much larger achenes of Bidens 
frondosa, as well as by the laxer habit of branching in the latter 
species. According to Wiegand the leaves are sometimes 
5-divided, but this was not observed in any Ohio specimens. 
