Sand Pine

01 Feb

Sand Pine

Pinus clausa


Friday John and George visited Seabranch State Park near Hobe Sound, a scrub area, or you might say a scrubby pine woods.  Except for a mantis praying, not much out of the ordinary, so we enjoyed the ordinary dominant Sand Pine trees.

Praying Mantis

Praying Mantis.  All of today’s photos are by John Bradford.

Two pines are native in our usual haunts, one being Sand Pine and the other Slash Pine. CLICK  Sand Pine tends to be a small gnarly hurricane-whipped scrub tree, although, given a chance, it can reach 60-80 feet tall.   They mature quickly, able under ideal conditions to form cones at under a year old, often reproducing by five years.  Yesterday we saw mature cones on the trunks of youngsters.  That’s one way of coping with fires and hurricanes: make seeds before trouble hits.

Sand Pine in the scrub.

Sand Pine in the scrub.

Todays the pines were maturing male cones resembling small yellow cigarettes, some already releasing pollen.    The emerging female cones are about the size of a pea, but scaly.  They take two years to mature into the familiar woody pine cones, and may remain on the tree for many more years until fire separates the scales and allows the seeds to fall onto the fire-cleared ground,

Young male cones.

Young male cones.

The Sand Pines in South Florida tend to have “serotinous” cones, that is, requiring fire to open up, although a walk in the woods shows some to open fireless.   “Clausa” means closed-in.  Oddly, there exists a second, northern, population in and near the Florida Panhandle separated from the southern distribution by a geographic gap.  The northern population has non-serotinous cones.  That is, they differ from the southern Sand Pines by having the cones open when mature and letting the seeds flutter without benefit of flames.

Young female cone

Young female cone

Now hold on there, that’s interesting.  To reiterate, we have a species spread the length of Florida with a gap in the middle.  North of the gap the cones open up, whereas south of the gap the cones wait for fire, although these tendencies are not 100%.  The difference has led some botanists to classify the northern open-cone-pines as one variety and the southern closed-cone-pines as a separate variety.   (Variety is a category below species in the classification hierarchy.  Species can be subdivided into varieties.)

This mature female cone opened with no apparent help from fire, even though it comes from the southern "closed cone" population.

This mature female cone opened with no apparent help from fire, even though it comes from the southern “closed cone” population.

The formal designation of two distinct varieties isn’t very convincing and doesn’t interest me much, but how that north-south difference in cone-behavior came about is something to ponder.  Three possibilities come to mind:

Possibility 1. Slow evolution.  Perhaps the two populations have been apart long enough for each to experience its own evolutionary divergence, with the cone difference being the most prominent distinction.  If that is so, was fire historically more a factor in the southern region than in the north?  Or could it be that in the cold north it is better to drop the seeds into the protective earth than dangle them in the frosty air?  (There are other serotinous pine species in northern regions.)  Of the three possibilities this one strikes me as most likely.

Possibility 2.  The southern population originating from a few closed-cone founders.  Maybe the Sand Pines originated in the north while most of Florida was submerged, and then maybe just by chance a closed-cone great ancestor jumped whatever gap(s) existed in prehistoric times to populate the southern region with its closed-cone descendants.  Scrub habitats at times of high water in millennia past were islands, and maybe a closed-cone “island” population developed and spread southward.  This possibility is called the “founder effect.”   There is a nice Wikipedia elaboration on this linked in the notes below.

Possibility 3.  Environmental cues.  Conceivably some environmental difference—soil, water, temperature—determines the cone type on any given specimen during its individual development.   If you have 10 years and a truck, you could plant some closed cone-types in the northern zone and vice versa and see if the reciprocal transplants each conform to their new digs.  Don’t hold your breath.

Possibility 4. None of the above, or a combination of factors.

Preliminary DNA study shows more variability within each of the two Sand Pine populations than between them.   In other words, DNA so far does not support recognition of two different named varieties, although there seem to be minor differences in their reproductive cycles.   The southern closed-cone types tend to be more uniform in age and in genetic variation (over small distances) than their northern counterparts.  Such uniformity might result from uniform repopulation after fire or hurricanes like grass regrowing uniformly after mowing, or maybe it comes from possibility #2, the founder effect, given that a small founder population would be less diverse than the large, widespread population to the north.







Posted by on February 1, 2014 in Sand Pine


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10 responses to “Sand Pine

  1. Jennifer Foglia

    February 5, 2014 at 8:02 pm

    This is such an amazing site! The amount of information you can receive just by navigating this site for a few moments is insurmountable. George Rogers is an incredible source of information and has put this site together in such detail it’s almost impossible to not find what you’re looking for in a matter of seconds. Of all the incredible things I’ve learned in his classes it’s hard to say I have a favorite plant I’ve learned about. I loved learning about the Coco Plum, the fact that it’s edible (although slightly mealy it does have an interesting flavor) is really cool, and also learning that the seed resembles a nuttier flavor of coconut I found it fascinating that it can be used as a source of fuel as well. Without George Rogers I wouldn’t have known that the invasive Australian Pine is not actually a pine! Either way, this site is an amazing navigational tool to find out about anything you would want to learn about any plants in Florida right down to the root systems and sustainable landscapes. Whether you are taking his class for a degree or just taking it to learn more about native plants of Florida, I highly recommend it! Thanks George Rogers for helping people be more knowledgeable about all things botanical, and thank you for putting so much of your time and energy into this site. It’s appreciated by many and keep up the good work!

  2. Jennifer Foglia

    February 5, 2014 at 9:36 pm

    Although my previous post wasn’t about the Sand Pine, I accidentally clicked on the wrong reply so here is my post about the Sand Pine (or scrub pine)! Every single ecosystem present here in Florida is so important to keep maintained and preserved because so many things rely on each other for survival. I did not know that the scrub pine was an important habitat for the endangered Florida Sand Skink. People don’t realize how many plants and animals rely on each others existence, and when one thing is thrown out of balance or removed from an area, so many other things die right along with it. In my last class with George Rogers, we started learning about the different indigenous pines and the many that aren’t that are used for landscaping and other things. The sand pine likes to be in very infertile sandy areas that need to be well drained. I love his plants of Florida class and would recommend it to anyone! He’s an amazing instructor

  3. Keith Rossin

    February 5, 2014 at 9:55 pm

    The Sand Pine really intrigues me the fact that i have lived here my whole life and have never heard the name sand pine is astonishing. Sand Pines occur in scrub areas with dry infertile soil, they also promote wildfires by letting the fire climb up there branches, this causes the Serrotinous cones from the fire and release the fire when heated with seeds on the bare soil stands of sand pines are usually the same age.

  4. George Rogers

    February 6, 2014 at 10:43 am

    An interesting problem with sand pine, it seems to me has to do with scrub management and fire. But I am not a scrub manager or a fire-maker, so I’m really just flapping my gums here from an outside viewpoint. Nonetheless, in an area where scrub is so reduced, as in PB County, I’ve read somewhere 98% of the original scrub is gone, the remaining scrub needs careful management under weird circumstances. The remaining scrub is sort of tucked in small patches in heavily settled/developed areas, making burning very tricky, perhaps not even possible in places. (And what exactly is the role of fire in scrub anyhow, what is the “natural” period between burns?) Left to thier own unburned devices, the sand pines can become fairly large and dominant. A nice example is the S end of the Jupiter Ridge natural area…the end where people do not go as often. As the sand pines rise up into a “forest,’ the “textbook” (early succession?) scrub disappears—the open sugar sand, FL rosemary, hogplum, pinweed, etc. etc. If that open sunny windswept scrub disappears, what creatures disappear with it? I mean, scrub critters are adapted probably to different succesisonal stages. What habitat exactly do scrub jays need? Do you manage for scrub jays, or for “natureal” growth? All that seems to me to be a big headache when you’re trying to deal with tiny postage stamps areas probably in some cases too small for minimum viable populatiosn of various creatures, with fire no longer a clear option as a tool, invasive exotics, and everyone wanting to build condos on the site…

    • Keith Rossin

      February 13, 2014 at 11:25 am

      I wish more scrub habitat existed it makes me sad to know we have destroyed 98 percent of our habitat that means we are likely not to see 98% of wildlife Florida a couple hundred years ago must have been a breathtaking place to row up to shore on.

  5. Erin Derwitz

    February 6, 2014 at 2:00 pm

    This site is great! I did not realize there was such an abundance of information on the topics I need for what I am studying right now in school! Our class recently visited Jupiter Ridge, where there are sand pines located in the scrubby flatwoods.They are not too large – but have many cones. I also learned that the scrub area is very old, and many of the rare and most endangered species approximately 90% come from the scrub woods. Also, some of the oldest habitats are currently now orange groves in Florida. We noticed on our field trip of numerous sea shells – this is due the water elevation of the ocean millions of years ago flucatuating – up and down. Also many fossils! I see that the scrub jay was brought up on this blog too.

    I learned in our lecture that the scrub jay, cacti, tortoise, etc have that “southwestern” appearance which could possibly be from a land connection from millions of years ago. I am happy to see more natural areas in Palm Beach County- this land needs to be preserved since there is so little left already! Thanks – Erin Derwitz

    • George Rogers

      February 6, 2014 at 7:36 pm

      Erin, Nice! to see you. Beautiful up on Jupiter Island today wasn’t it? Dee Staley is the resident blog Scrub Jay expert. Maybe she’ll continue that sometime soon…

  6. George Rogers

    February 13, 2014 at 11:51 am

    I sure agree wit hevery word of what you said. What’s even worse, postage stamps can’t support all the wildlife that belong in any given habitat. Make the area too small, and you start interfering with the overall ecology.

  7. Suellen Granberry-Hager

    February 20, 2014 at 10:03 am

    I enjoyed seeing the sand pine up close when the Native Plants class went to Jupiter Ridge a few weeks ago. I have a really tall slash pine in my backyard and can’t examine the living needles closely (only the dead ones on the ground). All or most of the pines in my area (very south Palm Beach County between the Turnpike and I-95) are slash pines, not sand pines, so this was the first time I have taken a really good look at a sand pine. Recently, I got to see some longleaf pines in DeSoto County and learned that they put up a white candela instead of the brown one seen in slash pines, which helps with identifying mature trees that are too tall for close examination of the needles.
    As far as habitat loss and fragmentation, people who think that tiny little plots of scrub or other types of habitat are suitable for wildlife should try living in tiny little houses in tiny neighborhoods surrounded by industrial areas and lacking necessary services such as grocery stores, gas stations, etc.

  8. George Rogers

    February 20, 2014 at 10:13 am

    Thnaks for the reminder on the pine comparison. And terrifc analogy. I think I’ll plagiarize it from you and use it in class.


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