There is limited water available in the deserts so plants tend to space themselves to avoid competition from other plants.
Plants are in competition for the little moisture available in the desert so tend to grow spaced far from their nearest neighbor.
Vociferous
Closely spaced
The spread of the Eva Cullum Phlox plant is between 2 and 3 feet.
50 feet
50 feet
15 meters
15 meters
50 feet
where isobars are spaced far apart.
50 feet
50 feet
at the least 10 feet...... maybe