478 COMPOSITAE (COMPOSITE FAMILY) 
TICKSEED SUNFLOWER 
Bidens trichospérma, Britton 
Native. Annual or biennial. Propagates by seeds. 
Time of bloom: August to October. 
Seed-time: September to November. 
ee _ Massachusetts to Georgia, and inland to Kentucky and 
nois. 
Habitat: Marshy meadows and swamps, banks of streanis, and 
often in drier situations, along roadsides and in waste places. 
Stem smooth, obscurely four-sided, two to five feet in height, 
much branched. Leaves pinnately three- to seven-lobed, with 
short, grooved petioles, the segments narrowly lance-shaped, 
pointed, and sharply toothed ; uppermost ones sometimes undivided, 
sessile or nearly so. Heads many, about two inches broad, on 
slender peduncles, in loose, corymbose clusters; involucre nearly 
hemispheric, the outer bracts linear to spatulate, extending scarcely 
at all beyond the broader inner ones; rays about an inch long, 
obtuse at tips, entire, bright golden yellow. Achenes narrowly 
wedge-shaped, crowned with two short, stout, three-angled awns. 
Despite its beauty, the weed should be destroyed in the same 
manner as Bidens frondosa. 
WESTERN TICKSEED SUNFLOWER 
Bidens aristdsa, Britton 
Native. Annual or biennial. Propagates by seed. 
Time of bloom: August to October. 
Seed-time: September to November. 
Range: Ohio and Michigan to Minnesota, southward to Mississippi 
and Louisiana. 
Habitat: Prairies, moist meadows, swamps, banks of streams, and 
ditches. 
Stem one to three feet tall, slender, and much branched. Leaves 
pinnately five- to seven-lobed, the segments slenderly lance-shaped, 
pointed at both ends, sharply cut and toothed, slender-petioled, 
softly hairy on the under side; upper leaves with fewer lobes on 
very short petioles, or lance-shaped and sessile. Heads numerous, 
one to two inches broad, on slender peduncles, in loose, open 
