DEPARTMENT REPORTS 53 



The plot of wild asters and goldenrods in like manner has recently 

 suffered much from certain insects working at the roots, as well as at 

 the tops, and several parasitic fungi have injured some of them. Insecti- 

 cides have been employed, still, from one cause or another, after a few 

 years, several species have been lost. In some instances it appeared to 

 be due to unfavorable weather. 



A number of species of sunflowers (Hclianthus) were nearly destroyed 

 by rust and mildew, and some patches became nearly extinct, where the 

 roots had slowly fed over the ground. A thrifty piece of iron-weed 

 (Vernonia) five or six feet in diameter nearly all died last year, as a hint 

 that a new place was needed. A little on the spreading margin was left 

 alive. 



After growing four years in nearly the same place, a thrifty piece of 

 EupliorMa dentata, an annual brought from central Indiana, all succumbed 

 to a rust, and EupliorMa nutans is likely to do likewise. I will say that 

 I have lately found a couple of healthy plants of Euphorbia dentata 

 near where the patch was located several years ago, and healthy plants of 

 Euphorbia nutans can be found in isolated places. 



1 have within twenty years seen numerous patches of shepherd's purse 

 become nearly extinct on account of attacks of Cystopus candidus, and 

 patches of knot grass nearly exterminated by rust. In some of these 

 localities a new crop, after a few years, sprang up where the ground had 

 been plowed. 



Where things have gone on in a rather monotonous way for some years, 

 certain insects settle down, live and thrive; meadow mice, moles, squirrels, 

 rabbits, muskrats — all learn the way, and the longer a plant remains in 

 one place in considerable quantity the more it is likely to be disturbed 

 by some of these enemies. As previously observed, the same may be 

 said of all sorts of rusts, mildews, microbes and the like. 



In mellow soil, such as the following plants delight in, the rootstocks 

 (in a few, the roots) run rampant in every direction, encroaching on other 

 plants and producing a mixture of species sometimes difficult to untangle. 

 Most of them are the pest of gardeners. Here are thirty-seven of them: 



Agropyron repens, Apios (tuherosa) Apios, Apocymun cannahiniim, 

 Aristolocliia Clematitis, Asdepias Snllivantii, Asdepias Syriaca, Bocconia 

 cordata, Capriola (Cynodon) Dadylon, Card^ius (Cnicus) arvensis, Carex 

 riparia, Carex trichocarpa, Couvolvnhis Sepium, CoroniUa raria, Cyperns 

 rotundas, Linaria (vulr/aris) Linarin, Lycium vulgare, Lycopus siiniatus, 

 Lycopus Virginicus, Lysimadiia Kummularia, Lysimadiia quadrifolia, 

 Lysimadiia (sirida) terrestris, Mentha piperita, Mentha (viridis) spicata, 

 Onodea sensihilis, Onodea Strutliiopteris, Poa pratensis, Populus alba, 

 Beseda Jutea, Rolnnia hispida, Rohmia Pseud acacia, Rohinia viscosa, 

 Sagittaria latifolia, Stadiys palustris, Te^icriuni Canadense, Thermopsis 

 CaroUniana, Tussilago Far far a, Tussilago Petasites. 



In our botanic garden, to keep some of these plants within reasonable 

 bounds, they were placed each within a piece of old smoke-stack a foot 

 and a half in diameter and about two feet deep. Some of the plants do 

 very well this way, but several of them leave the center vacant and run 

 around the edge of the enclosure, reminding one of uneasy animals in a 

 €age, while the Canada thistle thrives, putting its roots down deep into 

 the soil. The first you know, these roots of the thistle run under the 

 iron hoop and new plants pop up serenely from two to five feet distant. 



