BUREAU OF PLANT INDUSTRY. 263 



gradually to other susceptible hosts. Extensive rotation experi- 

 ments that are under way in the affected clover and alfalfa sections 

 give promise of an effective means of control. 



This nematode has also been causing losses in a number of large 

 commercial bulb gardens in the Northwest. Imported bulbs have 

 been found to be affected, and the possibility of the pest being widely 

 distributed on both imported bulbs and those distributed from in- 

 fested gardens in this country is being given serious consideration. 



Poisonous plants in 'pastures and ranges. — Following the prelimi- 

 nary botanical survey in June, 1922, of the areas in Texas where 

 the " loin disease " of cattle is prevalent, a second survey was made 

 in the following September. The principal areas where cattle have 

 died from this disease are in Harris and Brazoria Counties, al- 

 though some losses have occurred in Waller, Fort Bend, Mont- 

 gomery, and Galveston Counties. This is a region of flat wet prairies 

 and shallow ponds, ranging in altitude from 40 to 100 feet above 

 sea level. It is a difficult area to drain, and only a small portion is 

 under cultivation. Observed superficially it appears to be a fine 

 grazing region, but a critical examination of the flora leads to the 

 opposite opinion. The true grasses and browse of desirable kinds 

 are very scarce. Rushes {J uncus spp.) and swale grasses (Cy- 

 peracese) in the spring while tender are much eaten. Many other 

 herbaceous plants are represented, among which are Lippia cwiei- 

 jolia., Dauhentonia longifolia^ and species of Asclepias, Verbena, 

 Petalostemon, Helenium, Rudbeckia, and Baptisia. From what is 

 known of these plants none of them can at present be considered a 

 cause of loin disease. 



The poisonous-plant surveys on the ranges of Arizona and New 

 Mexico were continued, as a result of which our knowledge of the 

 identity and distribution of harmful species in this region has been 

 materiall}?^ extended. Particular attention was given to the occur- 

 rence of species of Astragalus, Asclepias, Helenium, Hymenoxys, 

 Lupinus, and Nolina, especially in the Apache, Coconino, Coronado, 

 Prescott, and Tonto National Forests in Arizona and in the Jornado 

 grazing reserve in New Mexico. 



As in previous years, specimens of all plants collected in connec- 

 tion with the poisonous-plant surveys have been deposited in the Na- 

 tional Herbarium. Since 1910 an average of more than 1,000 speci- 

 mens has been annually deposited, and in the current year the num- 

 ber was 2,400. In addition, many duplicate specimens have been 

 placed in the Gray Herbarium at Cambridge and in the herbaria of 

 the New York Botanical Garden, the Missouri Botanical Garden in 

 St. Louis, and the Field Museum in Chicago. 



Distribution of neio and rare field seeds. — A distribution was made 

 throughout the entire United States, having for its object the dis- 

 semination of seed of new and rare field crops, seed of improved 

 strains of staple crops, and high-grade seed of crops new to sections 

 where the data of the department indicate such crops to be of con- 

 siderable promise. Each package contained a sufficient quantity 

 of seed for a satisfactory field trial, and the recipient was urged to 

 use it, if feasible, for the production of stocks for future plantings. 

 A report card and a circular giving full directions for the culture of 

 the crop accompanied each package of seed. 



78007— AGE 1923 18 



