Thursday, April 30, 2015

Pursuit of Pawpaws

Most people are familiar with the song, "Way Down Yonder in the Pawpaw Patch."  I remember hearing this song as part of my childhood, but I never knew what a pawpaw was until I asked my grandma.  She told me it was a fruit that was about the size of an apple but shaped like a banana and that they were a greenish-yellow color.  She sang the song to me, but her version was a little different than the one I knew.  Instead of "picking up pawpaws and putting them in a basket," her version was "picking up pawpaws and putting them in your pocket."  After that discussion I never thought anything else about pawpaws until I became a naturalist.  

Pawpaw (Asimina triloba), is a member of the custard apple family (Annonaceae) and is native to the southeastern and midwestern portions of the United States.  Pawpaw is a patch-forming understory tree, although it is often more shrub-like than tree-like.  It generally favors rich, fertile bottomlands and upland sites with well-drained soils.  Individual patch members are clones of the parent tree, growing from root suckers.  Pawpaw displays large, simple leaves that are found on the ends of the branches.  The leaves give pawpaw a somewhat tropical look which does bring attention to itself when found in the mixed understory.

Several years ago, James Padgett and I were doing a plant inventory near Rainbow Falls in Hickory Nut Gorge.  James is a good friend of mine and is an inventory biologist with the NC Natural Heritage Program.  We were walking on the old trail to Rainbow Falls and we came upon a wet area.  Growing beside the seep was a pawpaw treeThis particular one was rather short and shrubby, but it was something at the time that was unfamiliar to me.  James quickly identified it and I readily admitted that I had never seen pawpaw before, at least if I had I didn't know what I was looking at.  I had seen pictures of the flowers in wildflower guides, but that was all the knowledge I had of the species other than that song that instantly began playing in my mind.  Of course this particular pawpaw tree was not in flower, but it was something I could add to my list as finally getting to see.  I have never seen pawpaw in Hickory Nut Gorge since that time.  I'm sure it occurs in other places in the Gorge but it is definitely a site specific species.

A few years after that, my niece had a birthday party on a farm in Bostic, North Carolina.  We were riding on a hay wagon to the party site and I kept noticing all these tropical looking short trees.  I was racking my brain thinking I had seen these trees before but I just couldn't identify them.  Finally, it came to me...pawpaw!  I mentioned it to the farm owner and he said he had never seen such a prolific stand of pawpaw trees anywhere.

Not too many years ago, local naturalist and entertainer Doug Elliott wrote a wonderfully, fascinating article about pawpaws for Wildlife in North Carolina magazine.  It was a great article and discussed the natural history of the plant and the edibility of the fruit.  After reading the article, I instantly went in search of the elusive plant in the hopes of finally seeing what the fruit looked like and hopefully even try one to see for myself what a pawpaw actually tasted like.

I found a nice little grove of pawpaws along River Road in Green Hill.  It was late September and there were pawpaws on the trees that were ripe and ready to drop.  I shook the trees and they came down and I scooped up the greenish, oblong fruits.  As it turns out, timing is everything when it comes to pawpaws.  In order for humans to be able to consume them, you have to get to them before the wildlife does.  Raccoons absolutely love them, as do gray foxes, opossums, squirrels and bears.  

Pawpaws are the largest North American native fruit, coming in at between 3 and 6 inches on average and nutritionally are very high in fatty acids.  They are also rich in vitamins.  I got the fruit home and quickly cut them in half along the seam that bisects them lengthwise.  The inside of the fruit was a rich cream color with several large dark brown seeds.  I discovered that the best way to eat a pawpaw was with a spoon.  The inside of the fruit has the consistency of custard and can be literally spooned out.  One of the remarkable things about pawpaws is that seemingly no one describes the taste the same way.  Some liken it to a banana, some cantaloupe, and still others describe it as being a little like a custardy mango.  My personal reflection on the flavor would be that I've never quite tasted anything like it.  Custardy is a good description.  I also noticed a hint of mint with maybe a little banana or pineapple flavor.  I was only able to eat just the one.  The custard texture was a little much for me, especially since I'm not much of a custard fan anyway.  To each his own I guess.

After tasting the long elusive pawpaw, I realized that I'd still never seen the actual flowers of the plant.    For those of you who read this and know me, one of my passions is nature photography, so it is only natural that I try to photo document the things that I see and write about.  The older I get, the more I discover that there are still things I don't have photos of so I set my goals accordingly.  Anyway, it was important that I track down the actual flower of the pawpaw, beginning a two year quest to find the plant actually in flower.

Timing is everything when it comes to wildflower photography.  You have to really know the bloom times and try to sync your photography schedule around those times, depending on the species.  There were two places that I set out to look for flowering pawpaw trees:  Green River Cove, which has a lot of pawpaw stands, and back to River Road where I collected my first pawpaw fruit.  March through May is the time to catch Pawpaw in flower so I timed it perfectly for getting shots of flowers.

I started in Green River Cove where I saw lots of trees but no flowers, except a few that were way out of the view of my camera.  This didn't give me a lot of hope because I feared that I may have waited too late to catch the best flowering time.  I worked my way back to Green Hill along River Road.  This was my last chance to get a good flower shot or else I was going to have to locate another stand of pawpaws.  As it was, my luck held out.  The roadside trees had flowers from top to bottom.  I was overjoyed.  I pulled out the camera and went to work.

The flowers were quite fascinating to me, particularly the deep venation on the petals.  There was no noticeable scent to the flowers, but literature describes the petals, when bruised do have a scent.  There are few pollinators, mostly flies and beetles that are attracted to the slight carrion smell that the flowers are said to possess.  I did not notice the smell, but then again, I'm not a fly either.

So now that this goal was completed, it occurred to me that my work was not done.  As it happens, there is another pawpaw found in our area that more often than not gets overlooked, but is every bit as important.  This would be the small flowered pawpaw or dwarf pawpaw (Asimina parviflora).  This plant was brought to my attention by another friend of mine and fellow naturalist, Ron Lance.  He discovered this plant at Chimney Rock State Park, growing in some dry woods near the Ticket Plaza.  I was again unfamiliar with this particular species and was just starting to learn about the big pawpaw, so I put it on the back burner of my mind to be on the look out for it.  

Several years would go by before dwarf pawpaw would cross my mind again.  Around the time I was getting my first taste of pawpaw fruit, I happened to be at my parents' house in the woods.  My stepdad and I were walking along a path and I stumbled on some chinquapin trees (Castanea pumila) and I remarked how I would love to find one with nuts on it (material for a future article I guess).  Anyway, I saw several more, none with nuts, but in the process of looking I stumbled on something that was odd to me.  There's not much in my parents' backyard that I can't identify but I had never noticed this particular plant before.  At first I thought it was an odd-looking horsesugar (Symplocus tinctoria) but then I got to looking a little closer and found old flowers.  I looked at the shape and instantly knew that I had found a dwarf pawpaw.

Dwarf pawpaw is tiny when compared to its larger cousin which is more tree-like than shrub-like.  Most dwarf pawpaws are rarely larger than 4 to 5 feet in height as opposed to the common pawpaw which can reach heights of about 35 feet.  The flowers are much smaller and are very fleshy but ultimately turn a deep maroon color as they age, similar to the common pawpaw.  The fruit are no more than a couple of inches and are round to oblong.  Like their cousins, dwarf pawpaws are important wildlife forage and grow in similar fashion.  Dwarf pawpaw seems to occur more frequently in the Piedmont than in the mountains, usually growing in dry woods or in sandy or alluvial soils.

Again, I set a goal to photograph yet another plant that had eluded me for quite a long time.  On April 26th, 2015, I was at my parents' house and remembered the dwarf pawpaw.  I wondered if it was flowering so I went and looked and sure enough, it was.  I went back the next day with my camera in hand and snapped several shots of the little shrub which was loaded with flowers but had not quite leafed out yet.  Finally an end to a long-time goal, with a satisfactory result.

Something else worth noting about both common and dwarf pawpaw is that they are the exclusive food sources for the zebra swallowtail caterpillar.  Pawpaw has some very potent alkaloids in the leaves and bark that make the plant unpalatable to most other insects.  When eaten by the caterpillars, it provides the caterpillars with a strong chemical defense against predators, particularly birds that might try to feed on them.  Some of those chemical defenses also provide pawpaws with a natural insecticide which can actually be extracted from the bark and leaves.  The insecticidal tendencies prevent insect predation on the plant by other species that might compete with the zebra swallowtail, excluding insects that extract nectar and help with pollination.  Pawpaws are easily grown from seed and are a choice landscaping plant provided that soil conditions are suitable.

It's always nice when you finally accomplish a goal.  Now I can finally sing the song and know what I'm actually singing about.  Getting the song out of my head, well that may not be as easy.  Until next time!