19. Elevation:

Elevations are usually given as a range, but if a single elevation is given it should be preceded by "ca." except at the beginning of a sentence where the word "About" should be used rather than "Ca." If only the upper or lower elevational range is known use "below" or "above" (e.g., "below 1500 m" and "above 4000 m"). Do not use "0 m" rather use "near sea level" and for a range use the word "to" followed by the upper elevation. For plants with a distribution that is above sea level but less than 100 m use "below 100 m." For plants that occur above 100 m round the lower elevation down to the next lower 100 m and the upper elevation up to the next higher 100 m elevation. The following examples show what should be used:

"0 m" becomes "near sea level"

"0--500 m" becomes "near sea level to 500 m"

"50 m" becomes "below 100 m"

"50--700 m" becomes "below 100--700 m"

"150--250 m" becomes "100--300 m"

"590--800 m" becomes "500--800 m"

"100--240 m" becomes "100--300 m"

"2020--2520" becomes "2000--2600 m

"3000 m" becomes "ca. 3000 m"