August Phenology

Following the hottest July on record (nationally as well as for Albuquerque), August shows no signs of letting up.  The heat continues near or above 100° every day.  The summer monsoon has largely been a "non-soon."  

Oddly, fall flowers are blooming early.  My current hypothesis is that the extremely early March warmth this spring has tricked some plants into "calculating" that 4 months has passed since the beginning of the growing season (normally April-May) and it's the correct time to bloom.  My bonsai deodar cedar is pushing fall foliage.  Meanwhile in the backyard, Ceratostigma (blue-flowered leadwort) and Chrysanthemum × morifolium (garden mum) are almost bloomed out.  Perhaps judicious dead-heading can prolong their flowering. 

This morning we knocked off another session of Nature's Notebook with mid-summer phenology observations.  The major debate today was on the ripening of Cylindropuntia (cholla) fruit.  I'll now pause typing this blog post while I dive into the online resources....

Lots of rangeland stuff about cholla eradication.  Most descriptions involve fruits turning yellow and then falling from the plant.  Folks at Nature's Notebook told Sandy that fruits that have lost their spines are ripe.  These descriptions seem to come from southern populations that I take to be C. imbricata var. spinosior.  

Our specimen, on the other hand, has persistent fruits that often take 2 seasons to finally drop from the stems.  Of course, by then they've progressed from yellow to a putty shade of beige.  They often turn green to yellow and back to green over the course of the season.  

The photo above, taken today, shows green, yellowish green, yellow, kinda orange, and putty fruits.  We'll be watching this group closely in the months ahead.  

One of the better illustrated resources is the Vascular Plants of the Gila from WNMU in Silver City, https://gilaflora.com/cylindropuntia_imbricata.html .  It shows yellow, spineless fruits in cross-section with pale brown seeds within.  It also mentions the low viability of the seeds.  

That's of little help to us with our spiny, persistent fruits.  Applying the Nature's Notebook rubric of ripeness as an indicator not of reproductive viability, but of value in the food chain, doesn't help here either.  

Reflecting on seed dispersal in chollas, the fruits appear fall in the immediate area of the parent plant.  Possibly they could attach themselves to the hide of passing large mammals.  I'm guessing that wherever the fruit land, they either have to weather for considerable time to expose the seeds or be broken open by some mechanical means like animal hooves.  Either way, I doubt if anyone is eating the fruits, unlike Opuntia, the prickly pear with its moist, dehiscent fruits at ripening.