Editing Eastern Prickly Pear (section)

===== Elevation =====

Prior to the discovery of the [[#Ingham Hill Colony (Old Saybrook)|Ingham Hill Colony]] at Old Saybrook, there seemed to be sufficient evidence that inland colonies of ''O. humifusa'' preferred elevations of between 350 and 550 feet above mean sea level (AMSL).  Since the discovery of the Ingham Hill Colony, though, this assertion has been seriosuly challenged and I no longer believe ''O. humifusa'' has any particular elevation preference.

With the exception of the Ingham Hill Colony, ''O. humifusa'' colonies upon inland ridges certainly present a tight correlation in elevation.  The [[#Metacomet Colony (Plainville)|Metacomet Colony]] is at an elevation of ~399 feet AMSL, the West Rock South Colony is at ~429 feet AMSL and both of the northern West Rock colonies range in elevation from ~515 feet AMSL at their highest to ~425 feet AMSL at their lowest.  These elevations are tightly clustered between 350 and 550 feet AMSL, which had hitherto lead me to believe that there was some advantageous quality to this range of elevations which ''O. humifusa'' preferred.  However, this theory seriously failed to account for those coastal colonies of ''O. humifusa'' that are found at significantly lower elevations (rarely exceeding 30 feet AMSL).  This fact was especially troubling when trying to determine some meaningful correlation between suitable ''O. humifusa'' habitat and elevation.

The discovery of the Ingham Hill Colony in Old Saybrook was particularly important, because the ''O. humifusa'' found growing there were at an elevation of roughly 145 feet AMSL.  This is the only instance that I have thus far encountered in which ''O. humifusa'' could be found at a distinctly intermediate elevation, significantly lower than colonies found on traprock ridges but significantly higher than colonies found in coastal scrubland.  Therefore, I have abandoned my previous suspicion that ''O. humifusa'' prefers elevations between 350 and 550 feet AMSL.  Instead, I would submit that the frequency at which inland ''O. humifusa'' occurs at these elevations is simply a product of the terrain of Connecticut, where the rocky cliffs of basalt ridges are very commonly found at elevations between 300 and 600 feet AMSL.

The Ingham Hill Colony proved to be something of a missing link, bridging the previously enormous gap in elevation between coastal colonies and inland colonies.