382 
timated 1,157 grass-plant individuals or 
tufts. This estimate was reached by di- 
viding the number of shoots in bunches 
and patches (4,051) by the number of 
shoots in a typical tuft (3 or 4, average 
3.5). There were in addition 247 shoots 
not aggregated into tufts or bunches. 
These were considered individual plants, 
as it was impossible to determine any un- 
derground connections without digging 
and removing these shoots from the mil- 
acre. The estimated total number of in- 
dividuals of 4. scoparius was 1,404. 
In the Phegley prairie, the shoots of 
Andropogon scoparius were mostly short 
and well separated, with very little lat- 
eral extension of the foliage. The open 
appearance of each bunch, the large pro- 
portion of bare ground, and the consid- 
erable ground area per shoot within the 
bunches were attributed to grazing and 
trampling by cows. Cows doubtless de- 
stroyed many shoots either by pulling 
them out or breaking them off and thus 
materially reduced the number of shoots 
per tuft. 
In the samples taken from ungrazed 
hill prairie in two sites, Northeast Mere- 
dosia and Reavis Spring, the number of 
shoots per tuft averaged between 3 and 4. 
In the mapped central milacre of the pas- 
tured Phegley prairie, the number of 
shoots per tuft was not so large; it was 
conservative to place the number of shoots 
per tuft at one-half that of ungrazed prai- 
rie, that is, 1.5 or 2.0, average 1.75. The 
1,143 shoots in bunches thus formed an 
Ittinotis NaturAL History SurvEY BULLETIN 
Vol. 26, Art. 5 
estimated 653 tufts or grass-plant individ- 
uals. In addition, 196 isolated shoots, 
representing that many isolated plant in- 
dividuals, were counted. The estimated 
total number of 4. scoparius plants was 
849. 
In the mapped Sampson milacre, 22 
shoots of Andropogon gerardi were found; 
19 of these occurred in one bunch. These 
19 shoots formed 11 plant individuals 
(estimated). With the 3 isolated plants 
added, the estimated number of 4. ger- 
ardi individuals was 14. A. gerardi did 
not occur in the mapped milacre in the 
Phegley prairie. 
In the central milacre of Sampson, 6 
bunches of Bouteloua curtipendula with 
43 shoots were mapped. These 6 bunches 
contained an estimated 12 plants. In ad- 
dition, 32 isolated plants were counted. 
The estimated number of individuals of 
B. curtipendula was 44. 
In the mapped Phegley milacre, 15 
bunches of Bouteloua curtipendula with 
108 shoots were charted. These 15 
bunches contained an estimated 31 plants. 
In addition, 25 isolated plants were 
counted. The estimated number of indi- 
viduals of B. curtipendula was 56. 
The ungrazed Sampson prairie con- 
tained an estimated 1,462 grass plants in 
the central milacre; the grazed Phegley 
prairie 905 in the central milacre. Table 1 
summarizes the above data. 
Plants Other Than Grasses —Of 
plants other than grasses in the central 
milacre of Sampson prairie, +87 plants of 
Table 1—Shoot counts and estimated numbers of bunch-grass plant individuals in the 
mapped central milacre of Sampson and of Phegley hill prairies. 
SAMPSON PRAIRIE 
PHEGLEY PRAIRIE 
Kinp of GrowTH| Andro- Andro- | Bouteloua Andro- | Bouteloua 
pogon pogon curti- Total pogon curti- Total 
scoparius | gerardi pendula scoparius | pendula 
Shoots aggregated 
in bunches... .. 4,051 19 43 4,113 1,143 108 1,251 
Isolated shoots.... 247 3 32 282 196 25 221 
TAT pe ae tee 4,298 22 75 4,395 1,339 133 1,472 
Plants in bunches | 
(estimated).....| 1,157 11 12 1,180 653 31 684 
Isolated plants 
(estimated)... . .| 247 3 32 282 196 25 papiil 
fi) a a | 1,404 14 44 1,462 849 56 905 
