182 Report of the Botanical Department of the 



ounce, 75 one and one-half ounces and 200 samples two ounces 

 or more. A purity test made from small samples can not be as 

 reliable as a similar test made from larger samples. 



Weed seeds found. — The following list shows the foreign seeds 

 that occurred most frequently in the samples tested. In nearly 

 all cases these seeds were present only in traces and the exact 

 proportion was not determined. 



Noxious Weeds. 



English plantain (Plantago lanccolata) occurred in 88 samples 



Chicory {Cichorium intybiis) occurred in 6G samples 



Dock (Rumeoo sp. ) occurred in 65 samples 



Wild carrot (Daucus carota) occurred in 33 samples 



Common Weeds. 



Green foxtail {Setaria viricHs) occurred in 377 samples 



Lamb's quarters {Chenopodium album) occurred in 225 samples 



Russian thistle (Salsola kali var. tenuifolia occurred in 171 samples 



Yellow foxtail (i^etaria glauca) occurred in 161 samples 



Sweet clover (Melilotus sp. ) occurred in 91 samples 



Brassica sp occurred in 76 samples 



Atriplex sp occurred in 76 samples 



Mallow (Malva rotundifolia) occurred in 50 samples 



Melilot (Melilotus sp.) occurred in 51 samples 



Centaurea repens occurred* in 52 samples 



Timothy (Phlcum pratense) occurred in 49 samples 



Catchfly (Siletie sp. ) occurred in 20 samples 



Alsike clover (TrifoUwm hybridum) occurred in 14 samples 



Koquette {Ertica sativa) occurred in 33 samples 



Johnson grass (Sorghum halapense) occurred in 26 samples 



Trianthema m,onogyna occurred in 26 samples 



Shaftal ( Trifolium suareolens) occurred in 16 samples 



Lance-leaved sage (Salvia lanceaefolia) occurred in 10 samples 



Barnyard grass (Echinochloa crusgalU) ,. occurred in 9 samples 



RESULTS OF RED CLOVER SEED TESTS. 



The 253 tests of red clover seed made during 1911 show that it 

 maintains its bad reputation as to impurities, the seed this year 

 falling below that of the previous year in purity. More samples 

 contained noxious weeds in considerable quantities, more con- 

 tained dodder, and two cases indicated adulteration. In general 

 appearance the seed ranks well ; for only 3 per ct. of the number 

 tested were graded below average. 



Weight of samples. — As with the alfalfa, many samples of red 

 clover seed were too small in weio-ht for satisfactorv determin- 



