2 8o THE COMPLETE GARDEN 



B. Skin Irritants: 



Primula obconica Rhus toxicodendron 



Hairy Primula Poison Oak 



Rhus radicans Rhus vernix 



Poison Ivy Poison Sumac 



Stipa spartea (skin irritant for animals only) 

 Porcupine Grass 



C. Causing Hay Fever. East of the iooth meridian in the 

 United States ninety per cent, of the cases of hay fever are caused by 

 the common ragweed {Ambrosia elatior) while in the Rocky Mountain 

 and Pacific states the sage brush {Artemisia) replaces the ragweed as 

 the most common hay fever weed. The so-called "rose fever" from 

 which many people suffer each year is not caused by roses at all 

 but by pollen from several different grasses. There are a number of 

 commonly planted ornamental plants which possess hay-fever produc- 

 ing characteristics, as follows: 



1. The flowers must be wind pollinated. 



2. The flowers must be very numerous. 



3. The flowers are generally unscented and not conspicuously 

 coloured. 



Some plants, like the goldenrods {Solidago), when used in large 

 quantities in a room may prove irritant, but the pollen is not wind 

 borne and thus it is not a true hay-fever plant. Dandelions have 

 been known to cause irritation when children press the flowers too 

 closely to their nostrils; but the dandelion is not a true hay-fever plant. 

 The list of plants given below has been divided into two parts: (a) 

 those plants which are active hay-fever producers, and (b) those which 

 are mild. None of these plants should be used about hospitals, nor 

 where hay-fever sufferers are likely to come in contact with them. 



a. Active: 



Artemisia frigida 



Wormwood Sage 

 Aster ericoides 



White Heath Aster 

 Aster novae-angliae 



Hardy Garden Aster 

 Carya ovata 



Hickory 

 Centaurea cyanus 



Old-fashioned Cornflower 



Chrysanthemum leucanthemum 



Ox-eye Daisy 

 Dianthus chinensis 



Chinese Pink 

 Miscanthus compactus 



Plume Grass 

 Eupatorium sessifolium 



Upland Grass 

 Helianthus angustifolius 



Hardy Sun-flower 



