Revegetation of Soil 263 



Various families of plants were never represented by more than 

 one species, as the Juncaceae by Juncus tenuis and the Liliaceae by 

 Asparagus officinalis, and the Portulacaeae by Portulaca oleracea. Other 

 families, on the other hand, were represented by several representatives, 

 such as the Cruciferae, the Leguminosae, the Euphorbiaceae, whose rep- 

 resentatives have grown especially well and numerously in the last 

 summer of 1921, as well as the Solanaceae and others. Oxybaplms nyc- 

 tagineus was brought by me from Harrodsburg, Indiana, more than 20 

 years ago and planted in my garden. Since then it has spread at 

 times more or less, but in such soil never in large numbers. It showed, 

 however, a tendency to spread. Early in the second year of these ob- 

 servations it traveled to this new area about 100 feet away. 



Next to the Gramineae the Compositae had during the two years 

 of observations the greatest number of species represented in this area. 

 Some of the genera were represented by numerous individuals, as would 

 be expected of the genus Taraxacum. The 120 different species that 

 were found on this area during the two years of observation were rep- 

 resented among other species of plants in the same vicinity. Especially 

 was this tru6 of some vacant land to the south of the area here dis- 

 cussed. This vacant land had for two years been in part plowed and 

 used for gardens, but in a very poor and unsuccessful fashion. This 

 land was weedy before plowing, particularly with Vei~nonia altissima 

 and Ambrosia artemisiifolia. Afterward this land was entirely neg- 

 lected and thus soon became a veritable pest-house for weeds. As this 

 tract lay just to the south across a road and about 70 feet away, it 

 thus became a very important source of weed infection of the area I 

 have discussed above. 



Barring its dense covering of weeds one especially was very con- 

 spicuous and numerous, namely Lactuca canadensis while Vernonia al- 

 tissima above mentioned was at this time represented by only a few 

 individuals and even these were, due to crowding and shading, by no 

 means as robust as when this land was an open meadow. 



The plants given in the following list for the area above discussed 

 are arranged for the most part according to the 7th Edition of Gray's 

 New Manual of Botany. 



Zea Mays, Setaria glauca, S. verticillata, Sorghum halepense, Digi- 

 taria filiformis, D. sanguinalis, Paspalum setaceum, Panicum Gattingeri, 

 P. Capillar-e, P. virgatum, P. microcarpon, P. huachucae, Axonopus fur- 

 catus, Phalaris canariensis, Phleum pratense, Sporobolus uniflor^ls, Ag- 

 rostis alba. Arena saliva, Danthonia spicata, Bromus secalinus, Cynodon 

 Dactylon, Eragrostis capillaris, Briza media, Dactylis glomerata, Poa 

 pratensis, Festuca ovina, Hordeum sativum, Triticum sativum, Secale 

 cereale, Juncus tenuis, Sisyrinchium angustifolium, Asparagus officinalis, 

 Juglans nigra, Carya ovata, Ulmus americana. Cannabis sativa, Rumex 

 crispus. Polygonum Hydropiper, Fagopyrum esculentum, Chenopodium 

 album, Amaranthus retroflexus, Celosia argentea, Phytolacca decandra, 

 Oxi/baphus nyctagineus, Anychia poh/gonoides, Stellaria media, Cerasti- 

 um vicosium, SaponaHa officinalis, Portulaca oleracea, Sassafras van- 

 ifolium, Draba verna, Capsella bursa^pastoris, Raphanus Raphanistrum, 



