70 
Colorado Agricultural College 
2. Northern Bedstraw ( G a l i u m 
horcalc L.) (Fig. 134). — Seeds cinnamon- 
brown to mummy-brown in color, broadly 
to nearly spherical in shape, deeply con- 
cave on one side, rounded on the other, 
rough, covered with bristly hairs; seeds 
1-1.5 mm. long, or across each face when 
circular in outline. 
32. RAGWEED FAMILY 
(Ambrosiaceae) 
Fruits (achenes) at maturity enclosed in either a beaked, bur- 
like or spiny involucre, or achenes winged or not winged; with 
pappus (growth or crown formation at the summit of the achene)^ 
occurring as hairs, scales or bristles. 
Key to Genera 
Seeds enclosed in an involucre at maturity 
Seeds armed with short, slender spines throughout l..Franseria 
Seeds armed with stout projections at the summit 2.. Ambrosia 
Seeds not enclosed in an incolucre at maturity ; seeds compressed, 
without hairs or pappus 3..7ra 
1. Poverty Weed, Bur Ragweed 
(Franseria, Cav.) 
Fruit (achene) enclos- 
ed in a spiny, beaked in- 
/olucre which becomes bur- 
iike at maturity ; involucres 
oval or nearly spherical, 
rarely splitting open at 
maturity. 
Poverty Weed (Fran- 
seria foment osa A. Gray) 
(Fig. 135).— Seeds light 
wood-brown to russet in 
color, armed with short, 
slender spines throughout; 
including spines, the seeds 
are 4-0 mm. long, .3.5-6 mm. 
wide, circular in cross-sec- 
tion. 
Fig. 134. Northern 
Bedstraw (Galiurr 
boreale). A. Side view 
B. Bottom view, x 12. 
Poverty Weed (Franseria tomentosa). 
X 12. 
IGg. 13.V 
