64 MIXXESOTA WEEDS 



Yellow Trefoil (Medicago lupulina L.) 



Other common names. — Black medic, black seeded hop clover, 

 none-such. 



Description. — Yellow trefoil is an annual belonging to the clover 

 family. It is grown in European countries as a forage plant on poor, 

 worn-out land. It is not considered a good forage p 1 ant in this 

 country. It is a low plant with wide spreading branches. It has 

 bright yellow flowers which are borne in roundish clusters at the end 

 of the branches. The pod which bears the seed is from one-twelfth 

 to one-eighth of an inch long. It is black and is kidney-shaped. The 

 pod clings closely to the seed which makes it difficult to thresh out 

 the seed. The seed itself is very similar to alfalfa and to the light 

 colored seeds of red clover, and has been used as an adulterant in 

 these seeds. 



The seeds arc greenish yellow and have a characteristic beak 

 coming from one side which enables one to distinguish the seed from 

 alfalfa and red clover seeds. The plant (lowers from the latter part 

 of May to October and usually ripens its seeds in July. It grows in 

 pastures and waste places, but is not very common in Minnesota. 

 It is troublesome only in rare cases and yields readily to cultivation. 



Sweet Clover (Melilotus alba Desv.) 



Other common names. — White melilot, white sweet clover, honey 

 lotus, tall clover, bokhara clover. 



Description. — Sweet clover may be cither an annual or a bien- 

 nial. It is not always a weed, but is esteemed in some sections as a 

 forage plant. It is often planted by bee-keepers because of its value 

 as a honey plant. There are two kinds of sweet clover, one with 

 while (lowers and the other with yellow. The white sweet clover, 

 which is most common in this State, is the one here described. The 

 plant makes a rank growth, often reaching the height of six feet, 

 with thick, much branched stems. The leaves and small white 

 flowers are nearly always borne on the side branches, and the flowers 

 are arranged in long clusters. The seed is encased in a small, brown- 

 ish pod and resembles thai of alfalfa or the light colored seed of red 

 clover. It is yellow, has a dull, rather rough surface, and has been 

 used as an adulterant in alfalfa and red clover seed. The plant 

 flowers in June and ripens its seeds in July. It thrives well in rich 

 soil thrOUghoul the State and is a common roadside weed. 



Eradication. Sweet clover is usually subdued by cutting before 

 the seed forms, for two years. It is rarely troublesome in the held 

 as it yields to plowing and cultivation. Many regard it as a valuable 



forage and hay crop. 



