286 ANNUAL, REPORTS OF DEPARTMENT OF AGRICULTTJEE. 



very inception that has been given the avocado. American avocado 

 growers are now equipped to proceed with the development of their 

 industry, with reasonable assurance that they have the best available 

 varieties as well as fairly complete knowledge concerning the culti- 

 vation of this fruit in other lands. In Dade County, Fla., nearly 

 2,000 acres are already planted to this crop. 



MENTHA CITRATA. 



Gratifying progress has been made in the introduction of Mentha 

 citrata^ a plant belonging to the mint famil}^ as a new volatile-oil 

 crop in this country. During the year this plant was grown at 

 Arlington Experiment Farm on a scale large enough to give definite 

 indications of its commercial possibilities. The yield of oil from the 

 plant when distilled was at the rate of 30 pounds per acre. The oil 

 itself is very fragrant and when fractionated yields 50 per cent of 

 linalyl acetate, a compound extensively used by manufacturing per- 

 fumers. If grown as a special crop under suitable conditions this 

 plant promises an acreage return equal to that now obtained from 

 other cultivated mints. 



ORNAMENTAL PLANTS. 



National rose test garden. — The plans for the future conduct of the 

 national rose test garden have been so modified that it is expected 

 that a large number of the varieties of mosses, briers, and centifolias 

 will be eliminated from the garden after the observations of another 

 3^ear. Meantime every effort is being made to complete the records 

 of these varieties so that all may go except those that will be kept 

 as index varieties with which to compare other varieties that may be 

 supplied for test purposes. The species collection transplanted last 

 fall is doing well. Progress is being made in preparing the stocks 

 upon which the tea and hybrid tea roses are to be budded for the 

 variety tests, and steps have been taken to begin the propagation of 

 roses on their own roots. The test will probably also include another 

 set of own-root roses propagated next season. 



Peonies. — With the peonj^ collection notes were taken this year on 

 the color of the early foliage and also on the duration of the flower- 

 ing season. As a result of a conference with members of the Ameri- 

 can Peony Society it is expected that more specific information will 

 be obtained from the collection next year and thus make the collec- 

 tion of more value. Several new varieties were added the past 

 spring, with the prospect that more than 200 others would be added 

 during the fall. 



CliTysanthemum'S. — The development of hardy early-flowering au- 

 tumn chrysanthemums which has been under way for several years 

 is being continued at the present time by the growing of practically 

 an acre of new seedlings. One of these bloomed this season in June. 



Iris. — Because several of the new European varieties of iris have 

 been added to the collection the past spring, with the prospect of 

 others coming in the near future, it has been determined to continue 

 the iris garden in order to make possible the comparison of these 

 new varieties with those now standard in the American trade. 



