EUPATORIUM FRANSERIA 273 



EUPATORIUM Linne 1753 BONESET, JOE PYEWEED 



(Named for Mithridates Eupator) 



Heads with white, blue or purple perfect tube-flowers, achenes oblong, 

 5-angled, pappus of hair-like bristles ; receptacle flat to conic, without chaff, 

 involucre hemispheric to oblong, bracts imbricated in 2-several rows ; heads 

 in cymose panicles ; leaves opposite or whorled, usually simple ; perennial. 



1. Leaves opposite, 1-2 in. long 



a. Bracts of the involucre nerved or ribbed E. Fendleri 



b. Bracts of the involucre not nerved E. texense 



2. Leaves usually in whorls of 3, 2-5 in. long E. maculdtum 



FILAGO Linne 1753 



(Latin filum, thread, ago, like, from the cottony wool) 

 Heads without rays, outer pistillate flowers in several rows, central 

 flowers few, perfect, mostly sterile, achenes flattened or rounded, pappus 

 none ; receptacle convex to conic with chaff, involucre of a few papery 

 bracts ; heads clustered, with leafy bracts ; leaves alternate, entire ; white, 

 woolly annual. 

 Stems 2-6 in. high; leaves spatulate, 8-15 mm. long F.prolifera 



FLAVERIA Jussieu 1789 



(Lat. flavus, yellow, from its use as a yellow dye) 



Heads with a single yellow, pistillate ray, 2-5-flowered, disk-flowers 

 perfect, yellow, achenes oblong or linear, 8-10-ribbed, pappus none ; in- 

 volucre of 2-5 equal bracts; heads in clusters; annual. 

 Stems 8-20 in. high ; leaves linear to lanceolate, en- 

 tire or toothed F. angustifolia 



FRANSERIA Cavanilles 1793 

 (Named for Franser, a Spanish botanist) 



Heads without ray-flowers, monoecious, staminate heads in terminal 

 spikes or racemes, pistillate heads solitary or clustered, achenes obovoid, 

 pappus none ; receptacle of the staminate heads chaffy, the involucre hemi- 

 spheric, open, 5-12-lobed, involucre of the pistillate heads globose or ovoid, 

 closed, 1-4-beaked, with several rows of spines, forming a bur in fruit; 

 leaves entire to pinnatifid ; annual or perennial. 



1. Leaves simple or once-pinnatifid F. Grdyi 



2. Leaves 2-3-pinnatifid 



a. Fruiting involucre 1 -flowered, its spines flat 



and thin ; annual F. acanthicdrpa 



b. Fruiting involucre 2-flowered, its spines short 



and conic; perennial 



