The End of September as We Know It

Nothing apocalyptic, I just like wielding the plowshare of drama as the months and seasons wheel around us:

As the pivotal month of September ended, my big columnar cactus (a small thing in a small pot many seasons ago) bloomed.  These blooms are about 6 inches across and open as the sun sets: quite spectacular in a backyard kind of way.

You (and I) would assume the pollinators for these flowers are nocturnal; moths, bats, vampires.  And that could be the case, but I was out at six a.m. to photograph the flowers and found small swarms of honeybees working the brush of stamens for pollen.  More than once in awhile one of the bees would land on or brush against the branched stigma with its pollen coated body, so the potential exists for bees as pollinators for this cactus.

About mid-day after blooming the flower has closed in on itself; still a few bees were seen crawling into the collapsed flower.  In this photo, there is a spent flower (left), a full bloom (center), and a bud (right) all atop the six ribbed seven foot stems of my cactus.  Notice the hairy bumps near the flowers.  These are I guess I would call them proto-buds.  They've been there for months, waiting for the proper stimulus (day length? temperature? age?) to develop into flowers.

Identifying tall columnar cacti with large white flowers isn't as easy as I thought.  I combed through photos and descriptions of many genuses, thinking it was sure to be one of the -cereus types.  But the hairy buds, short spines and bluish color along with other attributes led me to believe this is Echinopsis pachanoi, the San Pedro cactus.

My neighbor across the street has a huge cactus in her front yard.  You can judge the scale from the trash bins under it.  This cactus is not E. pachanoi; it has annually segmented stems that also branch, no hairy buds, more ribs, longer spines and is more of a yellow green.  But for whatever cactusy reason it is also in bloom here at the end of September.