THE PLANT WORLD UNDER CARE 



^:)D 



can be obtained should be put at once 

 into the hands of competent experi- 

 menters. 



What are we going to do when the 

 present varieties of potatoes have "run 

 out," and no more seed can be ob- 

 tained? 



United States Department of Agriculture, 

 Bureau of Plant Industry, Washington, D.C. 



Potato seed balls are frequently de- 

 veloped on potato plants grown in 

 northern latitudes. It is not at all un- 

 common to find a considerable number 

 of seed balls on potato vines in Aroos- 

 took County, Maine. Neither is it un- 

 common to find them in northern 

 Michigan and Wisconsin. I have also 

 seen them in a fair degree of abundance 

 in Greeley and Carbondale, Colorado. 

 Occasionally on certain varieties, they 

 may be developed quite abundantly in 

 this section of the country. We have a 

 collection of South American varieties 

 growing at Highlands, North Carolina, 

 which I hope to harvest this coming- 

 week that I am sure will supply us with 

 a considerable quantity of seed balls 

 of which I shall save a few for your 

 special use. On our seedlings of some 

 of our variety collection grown at Pres- 

 que Isle, Maine, this season, it would 

 have been possible to collect them by 

 the half-bushel. Unfortunately, I did 

 not have your letter at that time and 

 so did not save any. 



The reason that seedballs are devel- 

 oped more frequently in northern lati- 

 tudes is that in a colder and moister 

 climate the potato plant reaches its 

 optimum development and, under these 

 conditions they more frequentlv pro- 

 duce seed than under more imfavorable 

 ones. 



The reason why more seed balls are 

 not developed is due to the fact that 

 the plant fails to produce viable pollen. 

 — that is, pollen that is capable of ger- 

 mination. Whenever a variety is 

 grown that normally produces good 

 pollen in abundance one is almost sure 

 to obtain seed balls — Wm. Stuart, Hor- 

 ticulturist. 



The meeting last September, at Gen- 

 eva, of the Swiss Society of the Natural 

 Sciences, which corresponds in that 

 country to our own A.A.A.S., was the 

 hundredth anniversary of the Society's 

 foundation. 



The Shooting of the Pigweed. 



A purple specimen from the Amaranth 

 family in which are included our green 

 pigweeds as well as the tumbleweeds was 

 left at ArcAoiA by ]\Irs. G. Fred Farn- 

 ham, Sound Ijeach, Connecticut, who 

 found it in her garden in the autumn. A 

 lady in the office at the time said : "Isn't 

 that beautiful! I know what it is. It 

 is some member of the Celosia family.'" 

 The name Celosia brings to mind the old- 



A SECTION OF THE PURPLE PIGWEED. 



fashioned coxcomb of variegated colors, 

 more commonly purple. This sudden 

 identification would not seem so far out 

 of the way if one were to depend on a 

 casual glance at the beautiful color. But 

 the botanies as well as a little careful 

 observation classify the specimen far 

 from Celosia and list the plant asAmaran- 

 fliits paniculatns. Britton and Brown's 

 botany describes the seeds as follows : 

 "Fruit an ovoid or oblong utricle, cir- 

 cumscissile, bursting irregularly." The 

 seeds are tiny, shiny and black and are 

 shot out to an astonishing distance. The 

 specimen was placed on the table in the 

 laboratory and allowed to remain there 

 for three or four days. While examining 

 it. the seeds were seen to shoot out, some 

 of them to a distance of nearly a foot, 



