Leslie Sender 

 Extension Weed Specialist 



Supervisor in many SWCD's in Montana 

 recognize weeds as a serious Conservation 

 problem. The following article by Les Sonder 

 brings to our attention another serious weed. 



DALMATION TOADFLAX 



Dalmation Toadflax is a relatively new weed to Montana, 

 but is invading valuable grazing land quite rapidly. This 

 plant pest poses a great threat to our valuable grazing land 

 which is vital to the economy of the state. 



We are fortunate in knowing the potential seriousness of 

 this weed, by special demonstrations before the size of in- 

 festations become so large that eradication is impossible. 



This new pest has been found in Cascade, Gallatin, Lewis & Clark, Powell, Missoula, Lake, 

 Beaverhead, Meagher, Sanders, Flathead, Lincoln and Park Counties and may be in some that 

 have not been reported. Some of these counties have initiated an all out program to eradicate all 

 known infestations. However, cooperation is needed in all instances to locate and eliminate these 

 infesti.\Llons. Whenever an infestation is located, every possible means should be applied to era- 

 dicate dalmation toadflax and prevent further spreading. All known infestations are on or near 

 the headwaters of all major rivers in Montana. Eradication of this pest, while the acreage is 

 small, wi/i not only protect the grazing lands of Montana, but those in neighboring states. 



This pest seems to establish itself and thrive on dry, sandy, or gravelly slopes. It is generally ^ 

 found in areas that are partially bare, due to drouth, overgrazing or previously cultivated land. ^ 



Dalmation toadflax is a very hardy perennial capable of crowding out many desirable species 

 of rangeland plants. Idaho state research workers report that "Dalmation toadflax is very unpala- 

 table to livestock and hasn't been observed being grazed even when it was the only green plant on 

 the range." 



Dalmation toadflax was introduced from Europe to the United States as an ornamental species. 

 Even today it is occasionally found being grown in flower gardens as perennial snapdragon. Dal- 

 mation toadflax has a woody branching base and a medium to shallow, creeping root system. The 

 plant often reaches three feet or more in height. It is densely leafy with the lower leaves on the 

 stem somewhat narrowed at the base. The leaves of the middle and upper portion of the stem be- 

 come conspicuously broad-based. The flowers are deep yellow with an orange throat. The spur 

 of the snapdragon-like flower is long, straight or somewhat curved, and gradually narrows to a 

 point. 



Dalmation toadflax is very difficult and expensive to control. It is resistant to 2, 4-D when 

 applied at light rates. It has been necessary to use some type of soil sterilant to provide effec- 

 tive control. 



The use of soil sterllants on rangeland is an expensive proposition. This is why it is so Im- 

 portant to catch the weed when it is just getting a foothold. Early action can eradicate the pest 

 by treating the soil around the few starting plants. Successful control can be obtained by using 

 twenty Pounds (ten gallons) of trichloro-benzoic acid per acre, applied in 100 - 200 gallons of 

 water. T.B. A. is sold on the market as Trysben 200 or Benzac 1281. A granular compound con- 

 taining T.B.A. (Benzabor) applied at 200-250 pounds per acre provides successful control. 

 (Con't. Page 7) 



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