136 BOTANICAL GAZETTE . [FEBRUARY 
The quadrant below (fig. 5) gives the characteristic plants of a field 
which supported a crop of rye in the preceding year. Some fields may 
be controlled by Setaria glauca and Setaria viridis; others by Ambrosia 
artemisiifolia and Erigeron canadensis. Fields under observation 
TT latal Ta alt alew CTT TT ey Tent | aLlaL_ 
Lalal | | su T r) on Pal ] 
art Ca P PH sn | leu jas al la 
ajee7 H_JAL. aye 
A p SN A A al Ta = A 
SESR SE siee Al_ja{ [a \Reneer A 
g ae 3 ak PH we Bg Hitt J ‘SN A 
a a BS cc ee 
wat , | _}PH A PH | Pig SN 4 ; 
i ped Se ER Se 
P A a (a P 
PC pu_falal | [at fa lene He 
és J ptt tt ta A oe 1 | SW : 
PH PH A 1A} | 
ala n a fa ee seeeu 
A = A 
rt fs aT ten a 
rr PH J Bae 
aia_t al [a R Pore es 
\ ajay tT tt Tay je at | {tea {| | Sud 
\ A | IR 
& | | A af (J A Baer) BS A_jA 
Prerea a a A PH Jhamee 
a a AY jal Tt tT eat fe TT len_| | | Hey J 
p A a A J P [A [Al | 
A a Heal {3 
o A AIA A PH HA we 
E prt ae 
SH Ay_Jajal Ja} jee - 
A 
tt 
rT ar n aa PTT ter 
A rn Pu AlA PH app 
Sc Tae OR Ts Sel A PH Hi ry AJA ssid 
| P PH A | jA 
A iT iT SH | 
ry 
rele + p ar P ? PHA Ag CkwSE BRD PH 
>| [sw n A ofl are a fape A. 
AL| BNism, | lp {a ry oo 
SN 
PR eH Al | jew jt iad sn Ltt i |p TH CN a Og 
PH A eS ee ane 
A og One oe A | ja} | fa 
PHP A Rew ws 
P a ; is A ee rT fal | 7 
. aa ? a ay A 
PH [| JAJA PH JA aL TL [AL Palen A A sl 
ex CL Ta TCT fatale i 2 
ie a | 
Fic. 5.—Sample plot 24. Plowed field, abandoned one year, Colchester plain, 
I square meter; A, Ambrosia artemisiaefolia 155; PH, Phleum pratense 82; — 
olidago nemoralis 26; P, Poa compressa 14; PC, Panicum capillare 4; R, Rume 
Acetosella 7; J, Juncus sp. 6; E, Erigeron canadense 2; AL, Aster linariijolius t. 
for 4 years have remained under the dominance of these annuals. 
Later, Oenothera biennis, Rumex Acetosella, Gnaphalium poly- 
cephalum, Antennaria plantaginifolia, Solidago memoralis, and Aster 
linariifolius control the old fields in patches. Between these patches 
occur scattered groups of Cyperus filiculmis, Carex pennsylvanica, 
Andropogon scoparius, and Danthonia spicata. Groups of Poly- 
