Nts,
While in Arkansas, I wanted to make sure I saw Osage orange in its native habitat. Looking at maps, I stumbled across Bois D’Arc Wildlife Management Area. Given that bois d’arc is another name for Osage orange and Bois d’Arc Creek runs through the heart of the WMA, I figured might see Osage orange there.
- Bois d’Arc Creek
Perhaps fitting for Independence Day weekend, thousands of blooming American lotus captured my attention before I even reached the bottomland forests. Finger thick stalks raise the creamy flowers above the water like floral fireworks while the leaves the size of basketball hoops cover the shallows of the WMA’s central lake. The leaves are even substantial enough for wading birds to stand on and use as a fishing pads. Standing on the pads is probably a better idea than wading for the birds, because the lake is also home to alligators.
- American lotus (Nulumbo lutea)
- Bois d’Arc Lake
- Note bird in center of photo
Along the lake’s narrowly swampy outlet steam, Osage orange grows under water hickory and in association with American elm, cedar elm, overcup oak, and sugarberry. Slightly higher ground between that stream and Bois D’arc Creek supports a forest that was completely unfamiliar to me. Bottomland post oak and cedar elm dominate with more cedar elm, and sugarberry in the midstory. The broad oak crowns, tall and thick sedge and grass herb layer, and canopy recently opened up by selective harvest give the stand a savannah like feel. The dominance of bottomland post oak suggests calcareous soils, and the presence of a few shumard oak and nutmeg hickory reinforces that inference.
- Cluster of large bottomland post oaks
The edge of the stand along the levee also supports a colony of small trees I initially mistook for black locust with unusual bark. A later look at the leaves and immature fruits made it clear the trees were not black locust, but still left me with no idea which legume I was looking at. The trees turned out to be Texas sophora, a small tree primarily restricted to central Texas and found on calcareous uplands and along streams.
- Texas sophora (Sophora affinis) leaves
- Texas sophora
- Immature Texas sophora fruits. Fruits will turn black when mature.
Most of the other bottomlands along Bois D’arc Creek show stronger resemblance to bottomlands elsewhere in southern Arkansas and farther east. Away from the stream, willow oak dominates with cedar elm filling gaps in the canopy and cedar elm and sugarberry in the understory. Near the stream, cherrybark oak dominates along with willow and water oak, and shagbark hickory is common in the midstory. Less common species along the stream include sycamore, nutmeg hickory, and Osage orange. Overcup oak and to a lesser extent Nuttall oak were common in minor depressions, and water elm often grows out of the stream bank.
Common overstory species reach large but not exceptional sizes at the site, so I focused more on the uncommon species. Cherrybark is the generally the largest species where present, and reaches at least 11.5’ cbh. LiDAR has them to 127’, which looks about right based on a quick vertical shoot from the ground. Willow oaks come fairly close to matching the cherrybarks. Water oaks also exceed 10’ cbh, and some winter measuring might yield some over 110’.
- BoisDArcMeasurements.JPG (21.44 KiB) Viewed 2437 times
I feel like I never got into a good Osage orange stand. Most of the individuals I saw were about 2’ cbh, and looked young. The one I measured grows on the edge of what may be an abandoned pine plantation, and was simply one of the taller ones I saw. The largest were a little over a foot in diameter.
NTS has now measured two nutmeg hickories, but I hesitate to call the species under-measured. Nutmeg is the rarest hickory in the United States, so we may have measured a greater proportion of their total population than we have white pine. The one other nutmeg we have numbers for is the Georgia state champion, a taller but slimmer tree. This individual is by far the largest I saw, and is only about 13 points off of the national champion.
- 7’1” cbh x 99.7’ tall nutmeg hickory
The bottomland post oak is large relative to others I have seen, but I don’t have enough experience with the species to know just how large they can grow. Others nearly as large and taller were common at the site, so a more thorough search would likely turn up a larger individual. I have no idea if the Texas sophora is large or not.
- 10’3” cbh x 75.4’ tall bottomland post oak
- 1’10” cbh x 31.5’ Texas sophora
Jess
