April, 1905.] Notes — Ohio State Herbarium. III. 
319 
8. Bidens vulgata Greene. Stem stout, erect and branching, 
5-16 dm. high. Leaves pinnately 3-5-divided, on long petioles, 
leaflets lanceolate, acuminate, coarsely and sharply serrate or 
almost incised, 5-12 cm. long. Heads comparatively few, 
mostly on long stout peduncles, the largest becoming 2 cm. high 
and 3 cm. across in fruit, outer bracts 10-16, spatulate oblong, 
unequal and conspicuously exceeding the disk, ciliate at base; 
achenes brown, obovate, flat, 7—10 mm. long, the two awns 4-6 
mm. long. 
Abundant in moist soil throughout the state. It has long 
been confused with Bidens frondosa, and under that name has 
been included in Gray’s Manual and the Illustrated Flora. It is 
distinguished from Bidens frondosa by the larger heads, the 
coarser leaves, the more ascending branches, and the large broad 
achenes. The bracts, which are ciliate in Bidens vulgata, may 
possibly serve also as a distinguishing character. 
9. Bidens trichosperma (Michx.) Britton. Tall and freely 
branched above in the usual form, although in peat bogs it may 
bloom when but 2-3 dm. high. Leaves petioled, 1-2-pinnately 
parted, segments 3-10, narrowly linear-lanceolate or linear, 
acuminate at base and apex, sharply serrate along the middle or 
almost entire. Heads numerous and showy, outer bracts linear- 
spatulate, about equalling the disk; achenes cuneate, 5-6 mm. 
long, awns 2-3 mm. long, narrowly triangular, upwardly hispid 
or becoming smooth. 
Throughout the state, except possibly the extreme southern 
part, but especially common at the north. Widely varialfle in 
size and especially in the shape of the leaf-segments, which in 
specimens from peat-bogs are sometimes linear-spatulate, entire 
and rounded at the apex. From this extreme there is everv 
gradation to the typical linear-lanceolate shape. The varietv 
tenuiloha has been reported from the state and is undoulotedlv 
included in the preceding description, but there is no valid reason 
for separating two forms in the Ohio material at hand. 
10. Bidens aristosa (Michx.) Britton. Stems erect, freelv 
branching, 4-10 dm. high. Leaves petioled, pinnately divided, 
segments 3-7, lanceolate, sharply serrate, acuminate at both 
ends. Heads very numerous, with conspicuous rays, outer 
bracts oblong or oblong-spatulate, equalling or shorter than the 
disk; achenes broadly obovate, 4 mm. long, with two slender 
barbed awns 3-4 mm. long. 
This western species has so far been reported only from the 
western part of the state. Three specimens are in the State Her- 
barium, from Champaign, Clark, and Madison Counties. Although 
in general habit it resembles Bidens trichosperma, it is easily and 
certainly distinguished from it by the broad achenes with their 
long slender awns. 
