434 



CORRELATION OF DISTRIBUTIONAL FEATURES. 



Table 74. — Climatic extremes for region of cumulative occurrence of four species of grasses 



common in the great plains. 



Plate 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 43 

 44 

 45 



46 

 47 

 48 

 49 

 50 

 51 

 52 



53 

 54 



58 

 59 

 60 



63 



65 

 66 



68 



69 



70 

 71 



72 



Temperature: 



Days in normal frostless season (/s) 



Hot days, fs 



Cold days, fs 



Remainder summation above 32°, year (thousands) . 



Remainder summation above 39°, fs (thousands) . . . 



Exponential summation, fs (hundreds) 



Physiological summation, fs (thousands) 



Absolute minimum 



Normal daily mean, coldest 14 days of year (°F.) . . 



Normal daily mean, hottest 6 weeks of year (°F.) . . 



Normal daily mean, year (°F.) 



Precipitation: 



Normal daily mean, fs (inch) 



Normal No. rainy days (over 0.10 inch), fs 



Normal No. dry days (0.10 inch or less), fs 



Dry days, percentage of total, fs (per cent) 



Days in longest normal rainy period, fs 



Days in longest normal dry period, fs 



Mean total, year (inches) 



Evaporation: 



Daily mean, 1887-88, fs (inch) 



Total annual, 1887-88 (inches) 



Moisture ratios: 



Normal P/E, fs 



Normal w/E, fs 



Normal P/E, year 



Vapor pressure: 



Normal mean, fs (hundredths inch) 



Humidity: 



Normal mean, fs (per cent) 



Normal mean, year (per cent) 



Wind: 



Normal mean hourly velocity, fs (miles) 



Sunshine: 



Normal total duration, fs (hours) 



Moisture-temperature indices: 



Normal P/E XT, fs, remainder method 



Normal P/E X T, fs, exponential method 



Normal P/E XT, fs, physiological method 



Table 75. — Climatic extremes for total range of all species of Platyopuntias. 



Plate 

 34 

 35 

 36 

 37 

 38 

 39 

 40 

 41 

 43 

 44 

 45 



46 

 47 

 48 

 49 

 50 

 51 

 52 



Temperature: 



Days in normal frostless season (/s) 



Hot days, fs 



Cold days, fs 



Remainder summation above 32°, year (thousands) 



Remainder summation above 39°, fs (thousands) . . 



Exponential summation, fs (hundreds) 



Physiological summation, fs (thousands) 



Absolute minimum 



Normal daily mean, coldest 14 days of year (°F.) . , 



Normal daily mean, hottest 6 weeks of year (°F.) . 



Normal daily mean, year (°F.) 



Precipitation: 



Normal daily mean, fs (inch) 



Normal No. rainy days (over 0.10 inch), fs 



Normal No. dry days (0.10 inch or less), fs 



Dry days, percentage of total, fs (per cent) 



Days in longest normal rainy period, fs 



Days in longest normal dry period, fs 



Mean total, year (inches) 



