Curious Observation

In late November Leonard and I went to collect pine cones near Willow Creek Campground on California Highway 139 near Adin CA. Ponderosa (Pinus ponderosa) and Jeffrey pines  (Pinus jeffreyi), and hybrids of the two, are plentiful in that area. I wanted large conifer cones for a Holiday project.

There were plenty of cones, but about 98% of them were missing the peduncle (stem) portion of the cone. I naively assumed that for some reason Douglas tree squirrels (Tamiasciurus douglasii) were eating off the basal portion of the cone and discarding the remainder – perhaps like taking a bite out of a creme chocolate to see what flavor is inside. Leonard and I ranged far and wide and only found a few intact cones. I decided that the cones did not need to be “perfect” and we collected cones missing their tops.

Leonard and I remained curious about the cones because almost all were missing the tops, the cones were scattered all over the ground with no random scale detritus nearby and the peduncles on the few intact cones appeared to be broken or chewed off without a clean break as one would expect if the cone fell naturally. Leonard and I decided that the intact cones were ones the Douglas tree squirrels cut from the tree, dropped to the ground and forgot.

Since the intact cones were closed, I placed them in a warm oven in an attempt to open the scales. Much to my surprise, when I took the cones out of the oven the scales were  open AND a cap of basal scales and the peduncle had fallen away from the cone. The remaining cone looked exactly like all the other cones we found that were missing their basal scales. A new theory: the ponderosa and Jeffrey pine cones leave some of the cone on the tree when they naturally drop.

I searched all my reference books and did some other research, but could not find any information concerning the details of how the cones of those two pines fall. I even took binoculars and scanned the tops of ponderosa pines hoping to see cone “caps” remaining on the branches. The theory remained a theory.

This weekend Leonard and I were visiting a friend who showed us a wonderful book – “Forest Trees of the Pacific Slope” by George B. Sudworth published in 1908. (It is a beautiful book and I want a copy.) While paging through the book  I read in the section about ponderosa pines: “A characteristic of the cone in breaking away from the branch is that some of the basal scales are left on the tree.” Finally, here was evidence that our “theory” was correct. Mystery solved!! Thanks, Jim, for sharing the book.

The pictured cones are Jeffrey pine cones – the prickle at the end of the scales points inward.

I believe the birds will appreciate the pine cone feeders that Leonard and I gave all our friends – with or without the basal caps.


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