Editing Eastern Prickly Pear (section)

==== Status and Description ====

[[File:Ingham-hill-colony-o-humifusa.jpg|thumb|'''Ingham Hill Colony''', found on a sunny forest glade in the northern section of Old Saybrook, CT]]My field exploration in Old Saybrook revealed a single colony of ''O. humifusa'' living upon a rocky bald within a thick forest.  Named the '''Ingham Hill Colony''', it is comprised of what appears to be a single, large clonal cluster of approximately 20 to 30 square feet.

Associated herbaceous vegetation was restricted to sparse grasses and perhaps other inconspicuous low-growing plants.  As with all inland ''O. humifusa'' colonies discovered (as of May 28, 2012), ''Juniperus virginiana'' (Eastern Red Cedar) was a close associate.  The colony was essentially growing upon a rocky bald surrounded by a ring of ''J. virginiana''.

In quite a few ways, the Ingham Hill Colony is of special importance to further understanding Connecticut's fragmented population of ''O. humifusa''.  The colony can be found growing at an elevation of approximately 140 to 150 feet AMSL.  Previously, every colony I had documented was found either on coastal scrubland at an elevation between 5 and 15 feet AMSL, or upon rocky ridges at an elevation of between 330 and 550 feet AMSL.  To date, the Ingham Hill Colony is the only colony I have observed at this intermediary elevation.  This proves that my earlier deduction, that inland ''O. humifusa'' favors elevations from 350 to 550 feet AMSL, is not necessarily true.

In addition, the composition of the soil upon which the Ingham Hill Colony is growing is also quite exceptional in juxtaposition to all other previously-documented inland colonies of ''O. humifusa''.  According to the Soil Survey of the Connecticut, the Ingham Hill Colony is growing upon '''Charlton-Chatfield Complex''' (Soil Type 73) which is sub-classified as "15 to 45 percent slopes, very rocky" (Soil Type 73E).  This soil type, which is derived variously from granite, schist and gneiss, is a notable diversion from the Holyoke soils (Soil Type 78) upon which all other inland colonies of ''O. humifusa'' have been discovered, indicating that the cactus is not likely to have any particular affinity for soil derived from basalt, diabase and gabbro, as previously believed.  However, this soil type does coincide with other habitat requirements of ''O. humifusa'', being well-drained and "very strongly acid to moderately acid".