Native Trees of the WeekNovember 27th, 2012 at 4:17 pm by Chad Evans under Chad's WLFI Weather Blog
NORTHERN PIN OAK (Quercus ellipsoidalis)
GLACIAL SURFACE GEOLOGY & THE NORTHERN PIN OAK…………
At the end of the Wisconsin Ice episode or end of a series of Ice Ages (Pleistocene) that totally buried the ancient Teays River Valley & leveled the landscape in our area, much water remained from the melting ice. With the land totally re-worked, the land was considered geologically young…………….& still is. Water was back-upped by piles of sand & soil left over in the geologically-young land, scraped from Canada & large, large areas of stagnant water, unable to drain sat. With time, such water drained as the ice totally receded & the sediment laid down became wind-borne as winds were very, very strong in a band south of the great ice sheets. This wind blew the sand & silt into rolling drifts across Newton, Jasper, Pulaski, Fulton, White & Cass counties. Such sandy dunes make a lot of land in our northern counties in need of irrigation for crop production in the summer. These were & still are the haunts of Northern Pin Oak (also known as Hill’s Oak). Dry, sandy savanna & prairie is its home.
A tree of these wind-blown dry, droughty, sandy dunes, mixed with Black Oak savannas of northern Indiana, Northern Pin Oak is an over-looked native tree. Though farming has eradicated much Northern Pin Oak, this tree formed thickets, scrub & scattered trees on the prairie dunes & savannas. In fact, this species, with Black Oak, formed a transition between the large prairies & the oak openings as one moved eastward from Jasper & White to Cass & Pulaski counties. Very drought tolerant, Northern Pin Oak is so intolerant of shade that its own limbs will die off & shed if its own foliage shades it self. Very fire tolerant, it is a substantial component of the sand savanna & prairie environment in northern Indiana & it usually found with Black Oak. In fact many dunes that are labled purely Black Oak savannas contain much Northern Pin Oak, but they all just seemingly blend together.
It is also a component of the original “oak openings” throughout northern Indiana on typical loam & clay loam soils with bur, shingle, scarlet, white & black oak with hickories in that transition zone between largely beech-maple forests & the prairies to the west. It also has an affinity for the gravelly, rather sandy slops of glacial kames (gravelly hills) & eskers (snake-like ridges of gravel & coarse materials that were deposited by streams of melt water within the ice sheet). However, it seems to have issues with competition from Bur Oak in these areas, so is most common on the sandy dunes.
NORTHERN PIN OAK’S ATTRIBUTES………….
Vibrant in orange & scarlet fall color, this species has a nice form with broad crown & fairly short stature with a peak height of 50-60′, but may spread out nearly as much. Its shiny foliage, fall color & decent form, as well as durability to droughty, coarse & hard, clayey, dry soils has made it a bit more popular recently in the nursery trade. It grows reasonably fast & for the first time, I saw it offered at a nursery in Lafayette this summer. It doesn’t really need any irrigation in summer drought, even if planted on the driest gravelly soils. The only issue is its self-pruning, as it sheds a lot of snags & dead branches with age & tends to have quite a few dead branches in the crown as it matures. However, this attribute made it an important nesting site for savanna-loving eastern bluebirds. Before European settlement, bluebirds were THE savanna bird, loving grassland with oak openings & scattered trees. The fire-scarred oaks with decay were perfect for cavity nesting. Northern Pin Oak provides nice snags & cavities for this colorful native thrush.
Northern Pin Oak likes to hold onto its leaves through winter, as dry, brown, crispy foliage. Entire young trees will be clothed in foliage all winter, until pushed off in the spring. Older trees with have a brown, dried foliage skirt on their lower branches.
For germination, this tree must have 95-100% light & rather bare, mineral soil with little competition. It can contend with some little bluestem & dropseed grass competition, but cannot handle lots of vines, trees & plants crowding it. It likes a fire regime to accomplish this, as it will even bud as a young tree after fires (as long as they are not overly frequent).
POST OAK (Quercus stellata)
If Bur Oak is the tree of the black loam prairies & savannas in northern Indiana & Black Oak is the tree of the sandy prairies & savannas in northern Indiana, then Post Oak is the tree of the gray prairies & barrens of southwestern Indiana. It is certainly a more southern oak in the U.S. with large amounts of Post Oak on the Blackland prairies of Texas & Oklahoma. It is frequent in the southern U.S. pine barrens & in the Karst barrens/prairie region of Kentucky & Tennessee. It cannot not thrive in a closed, crowded forest situation & survived in either a regime of fire or on really poor, dry sites where other trees cannot crowd it. Where it is found on the richer soils of southwest Indiana, it was historically maintained by fire.
An isolated native population of Post Oak exists on the sandy/gravel slopes near Wea Creek in Tippecanoe County. The closest population outside of this is in northern Clay County, Indiana near Route 159 & 246 intersection (a good 85 miles to the south), where I found several individuals growing mixed with White, Shingle & Black oaks, as well as Shagbark & Mockernut hickories. Open woodland was on an upland slope of thick silty loess overlaying Illinoian glacial till. Native vegetation of this area was prairie mixed with barrens & ribbons of timber. It was south of the large prairies running from Prairie Creek & Prairieton, Indiana to Blackhawk, Lewis & Clay City, Indiana.
This Tippecanoe population is an outlier from a much warmer, drier time in Indiana when Post Oak’s range greatly expanded to northern & central Indiana, before being crowded out & dying out by cooler, moister times in the climate pendulum. Like a tidal pool, southern & western species’ ranges shrunk with the wetter regime & the island of more southern & western species remained along the sandy & gravelly areas around Granville. This Post oak population may date back to Medieval times, perhaps the Hypsithermal.
There are really three types of Post Oak in Indiana that may be vague subspecies.
One grows on the gray prairies/barrens region of southwest Indiana on the silty loess soils & clay-loam soils of the region (Western Illinoian Till Plain). In far southern & southwestern Indiana, it grows on clay soils of the Driftless area on acidic flatwoods, often on soils with a fragipan or a hard pan layer restricting downward movement of water. It also grows in Black oak woods with hickory on dry, upland, south-facing slopes of the Driftless area. It grows on higher flatwoods on the old lake plains (lacustrine soils), clay soils of southern Indiana, too. These lake plains are layers & layers of silt & clay from trapped glacial meltwater settling in this part of the state during the Pleistocene.
In pre-settlement barrens areas of Spencer & Warrick County (nature area to view this environment: Bloomfield Barrens Nature Preserve), the Post Oak grows on those clay flatwoods that are acidic & have a fragipan or pan in the soil that restricts downward movement of water. They are wet in spring & bone-dry, desert environments in summer & fall.
Often a southern barrens & prairie indicator species, Post Oak is found with red cedar, blackjack, black oak in rocky glades on high, south-facing slopes in south-central Indiana hill country. I also grows with Chestnut Oak & Virginia Pine in the “knobs” area of far southern Indiana on rocky slopes. Post Oak is found on the Mitchell Karst Plain in former barrens & prairie areas with Black, White & Blackjack Oak & hickories from Orange through Washington & Harrison County, Indiana.
Closest associates to Post Oak in this area: Swamp White Oak (Quercus bicolor); Shingle Oak (Quercus imbricaria); White Oak (Quercus alba); Black Oak (Quercus velutina); Shagbark Hickory (Carya ovata); Mockernut Hickory (Carya tomentosa)
POST OAK TYPE #2: POPULATION A NORTHERN PROTRUSION CLOSELY-RELATED TO DELTA POST OAK (A SUBSPECIES THAT IS LARGER, MORE VIGOROUS & GROWS WITH OTHER HARDWOODS IN THE HIGH BOTTOMS OF THE MISSISSIPPI RIVER VALLEY) IN FAR, FAR SOUTHWEST INDIANA
There is a different genotype of Post Oak that grows faster, gets larger & is better able to compete with other oaks in Posey & Vanderburgh counties in Indiana. It competes with the Southern Red Oak, Cherrybark Oak, Pin, Swamp White, White Oaks in flatwoods of this area well & gets to be a very large tree up to 100′. This genotype is more closely-related to a subspecies of Post Oak called Delta Post Oak. In fact, this population may be a northernmost protrusion of Delta Post that has naturally hybridized with the typical southwest Indiana Post Oak.
Closest associates to Post Oak in this area: Winged Elm (Ulmus alata): Southern Red Oak (Quercus falcata); Cherrybark Oak (Quercus pagodafolia) Swamp White Oak (Quercus bicolor); Shingle Oak (Quercus imbricaria); White Oak (Quercus alba); Black Oak (Quercus velutina); Blackjack Oak (Quercus marilandica); Shagbark Hickory (Carya ovata); Mockernut Hickory (Carya tomentosa); Shellbark Hickory (Carya laciniosa)
POST OAK TYPE #3: MORE RELATED TO SAND POST OAK (GROWS ON DRY EOLIAN SAND HILLS OF LOWER WABASH & WHITE RIVER VALLEYS IN SOUTHWESTERN INDIANA)
There is a type of Post Oak that is restricted to the sand hills of southwestern Indiana. It tends to be shorter & squatty compared to the gray prairie Post Oak & will not grow in loam or clay soil well at all. It grows in the very well-drained Eolian sands bordering the east side of the Lower Wabash & White River Valleys. I have tried to plant the sand Post Oak on gray prairie or loess soil & the tree never survives. The sand barrens Post Oak genotype is different than the Post Oak of the gray prairies. It is more related to the subspecies of Post Oak called Sand Post Oak, which is not found in Indiana.
Closest associates to Post Oak in this area: Blackjack Oak (Quercus marilandica); Black Oak (Quercus velutina); White Oak (Quercus alba); Chinkapin Oak (Quercus muhlenbergii); Sand Hickory (Carya pallida); Arkansas Black Hickory (Carya texana var. arkansana);
Post Oak is generally a slow grower. In acorns I germinated from a Post Oak woods on an old prairie 40 miles northeast of Vincennes, Indiana (Odon, Indiana), the trees are just above my waste (I am 6’3″)& I germinated them in 2001. The same redbud trees I germinated are over my head now. A tuliptree I planted at the same time & was 1′ tall, is 20′ tall at the same site! I just keep thinking I really won’t see this Post Oaks do much until I am 60 or 70 years old! Truly, it takes a lifetime from seedling to even start to see Post Oak tree really develop.
It is like Shingle Oak in that it cannot tolerate shade & needs warm, open areas to germinate. It cannot compete with most other species well. The genotype more closely related to Delta Post Oak is much better at competition & some shade than the other genotypes. When Post Oak reaches 150-200 years old, though, it is a magnificent tree & still ranks as one of my favorites. I have seen 200-300 year-old Post Oaks in the open that resemble the idyllic very old English Oaks of the British countryside.
Its bark resembles White Oak to sometimes Swamp White Oak, its old limbs are often contorted, twisted & picturesque. It hold its dry, rusty foliage into the winter, especially on younger trees & lower limbs.
Tolerating fire as good as Bur Oak, it sprouts well after a burn & was a main species with Black Oak in the “oak stool” environment of the Karst prairie & barrens in far south-central Indiana at European settlement. Each fire burning over the Post Oak would initiate healing of burned, thick bark, causing large chunks of tissue to form above & just below ground. These reportedly made plowing the virgin reddish Karst soil difficult as these oak stool would break steel plows. This would form thickets & shrubbery of Post Oak.
Being a slow-grower, Post Oak puts a lot of energy into growing deep roots (specifically tap root when young) & put dense, dense rings into the wood. The wood is very heavy & resistant to rot.
Post Oak barrens/savannas:
Leaves, acorns, bark, shape & early fall color of Post Oak:
AMERICAN BEECH (Fagus grandifolia)
AMERICAN BEECH IS A RATHER SENSITIVE SPECIES THAT REQUIRES THE FOREST ENVIRONMENT………….
If you have large beech trees on your land, more than likely, the land was forest at the time of settlement. American Beech is strictly a forest tree. It doesn’t like direct exposure to the elements, doesn’t like open, exposed countryside, prefers shade & has bark so thin that it blisters very, very easy in the elements. The tree does not tolerate drought well at all & needs sustained, persistently moist soil through the year. The species also is intolerable of fire. Even a low fire will severely blister beech bark, especially on younger & pole sized specimens. It will greatly weaken older trees. Heat & drought will wither foliage & cause scorch much like Ohio Buckeye, especially in soils that are exposed. The tree is also very susceptible to construction projects, as it does not like it roots disturbed or elevation changed in any way. Many times, when homes are being built or subdivision constructed, it is hard to save the beeches if you want a more wooded subdivision if any soil is moved around the tree. Some may make it for a while, but boy do they struggle.
AMERICAN BEECH’S NATURAL ABSENCE IN CHUNK OF THE VIEWING AREA………….
In our viewing area, it is highly-likely that there were no beech trees in Newton, Jasper, Benton, White & Pulaski counties at settlement with beech confined to the deeply-eroded ravines of creeks & streams in Tippecanoe, Warren, Fountain, Montgomery & Carroll counties. Its occurrence tended to be higher in Tipton, Howard, Miami & parts of Fulton counties. In parts of the viewing area there is a real dicotomy in natural areas & native vegetation, largely due to geology & geomorphology. An area I like to call the Sugar Creek Entrenched area is a natural division where glacial meltwater & floods have carved out picturesque canyons & ravines in areas of thinner glacial till. This environment is common in Turkey Run & Shades State Parks, as well as areas in Warren, Fountain, Montgomery, through Tippecanoe to Carroll, Cass, Miami & as far northeast as Huntington. These deeply-eroded ravines are cool, moist, forest environments with lots of beech, sugar maple & tuliptree. They are refugia for forest species in an increasingly prairie biome. This habitat has acted as a refugia for odd, disjunct populations of Eastern Hemock, Canada Yew & native Eastern White Pine in Turkey Run, Pine Hills & Shades State Parks (pocket populations left over from the cold, wet climate at the end of the last Ice Age).
3 TYPES OF AMERICAN BEECH IN INDIANA………..
TYPE #1: Southern Flatwoods Beech
There are 3 types, subspecies or genotypes of American beech in Indiana. The first type has a much greater tolerance of wetter, tighter, clayey soils compared to the other two. With genetic origins in the southern U.S., this beech is a significant part of the dense flatwoods forests of southeastern Indiana. Here a strictly pin oak-sweetgum-beech-red maple forest formed pure stands. Here, it not only grows densely in the understory of the flatwoods, but also in the overstory with large specimens in nearly pure stands in older forests. There are some areas in the Driftless area of southwestern Indiana & in the southern bottomlands region of southwestern Indiana where you can find this type of beech. I have actually seen this beech frequently with Cherrybark Oak (Quercus pagodaefolia) near the Ohio River in Spencer & Perry counties in Indiana & frequently with Sweet gum in Pike County & Dubois counties in southern Indiana. In these areas, it tolerates standing water well, but cannot tolerate deeper river flooding.
TYPE #2: Appalachian Beech
Trees in the hill country of south-central Indiana have more of an Appalachian origin. It is usually accompanied by more mesophytic species like tuliptree, various oaks & hickories, white ash, maples, basswood. These beeches grow on lower slopes, usually with a north-facing tendency & in coves where it likes the company of tuliptree & maples.
TYPE #3: Central & Northern Till Plain (& Moraine) Beech
Finally, in central & northern Indiana, beech is apart of the maple-beech belt from the till plains of Ohio & Ontario, where it is usually accompanied by American basswood, White Ash, Sugar & Black Maples & Chinkapin & Northern Red Oak. In this often calcareous glacial till, the species formerly formed pure stands & is considered a climax species with maple in these areas.
In the eastern part of the Tipton Till Plain & Northern Lakes & Moraine Region of Indiana, however, it is a relatively new tree to the landscape. Pretty Lake corings in Noble County (Williams, 1974) indicate that Beech largely arrived at that location just prior to the Hypsithermal (main prairie period of hot, dry weather with climate here more like Oklahoma or Nebraska) with greater frequency than currently, then radically dropped in numbers for about 2000 years (prairie & oak pollen skyrocketed at this time & remained very high until an all-time peak [at least in the 14,000-year coring], roughly 2500 years ago) until its greatest extent in the 14,000 years of the coring at 1500 years ago. Since that time, it has declined, but has seen resurgence in recent years in the understory of nearby woods. There is a bit of beech pollen for a few hundred years centered around 9000 years ago, when pine pollen had radically diminished.
There is also a tiny pulse of beech pollen around 13,000 years ago that was found for about 300 years with a little spike in hornbeam, elm & pine pollen in the set (with LOTS of spruce pollen & a bit of fir [fir pollen peaked around 10,500 years ago in the data set]).
It is interesting that other than that 9000 year old small stretch of minute amounts of beech pollen, that no beech was found on the site or nearby for another 2500 years after glacial ice recedence, but ash, elm, hornbeam & at least some oak pollen had been on site since the very tail end of the glacial ice.
Beech nuts are very oily, fatty & high in calories, making it an important food source for wildlife. An interesting, triangular nut, beech oil can be extracted from it & can be used in a lantern to burn. The triangular nuts are enclosed in a spiny, bur-like husk on the trees.
Beech is easy to spot in the forest in winter. Young floor & understory beeches retain their leaves through the winter. Highly sensitive to wind & ripping, the papery, thin leaves are tan/peach colored to rust color when retained on the trees.
As beech gets very old, it tends to hollow-out in the middle & eventually, topples from this at 300-400 years of age. Large, hollow beeches provided important nesting habitat for chimney swifts in forest openings prior to chimneys. My dad told me a story of how when we was a kid in the 1950s & 1960s there was a gigantic beech near Raglesville, Indiana (45 miles south-southwest of Bloomington) near my relatives’ that all of the kids would play in. In typical old, old beech fashion, the tree was hollow & provided a natural cave for all the country kids to play in. Dad still remembers how gigantic this old tall stump was.
SHINGLE OAK (Quercus imbricaria)
This member of the Black Oak group is the oak with its conspicuously oblong, shiny, rather leathery leaves that tend to brown, dry & tend cling to its twigs in winter. We called it “Peach Oak” growing up in southwest Indiana (due to the leaves that look a bit like those of a peach)& also (I hope no one is offended by this, but farmers where I grew up called it this) P-ss Oak, as the wood emitted a uriney odor. In the History of Clarksburg & Early Odon, it was called “Shingle Tree”, as the wood splits very well for shingles & was used for such exhaustively in pioneer times.
Shingle oak is THE tree of the gray prairies & barrens in southwestern & western Indiana. No where in the state does it reach greater occurrence than there. As a kid, remember seemingly every old farm fencerow having Shingle oak, mixed with the sassafras & black cherry, of course in traditional gray prairie & barrens areas. Many times, I would go into the fencerows & dig out Shingle Oak seedlings in fall & winter to transplant (they are pretty sensitive too it, though…………you can only do it in late fall or spring, as it has a heck of a tap root. You have to get lots of lateral roots when you dig it). It is a barrens species on the loamy, clayey loess & Illinoian till soils that tend to be on the acidic side. “Gray” is a term to describe the soils of that region, as they lack the deep chernozem soils of Benton & White counties of those prairies that were there for a long, long time. The ashen-gray to dark-gray soils tended to have prairie & barrens on them in a state of flux. It wasn’t solid prairie for thousands & thousands of years, but a pendulum of back & forth, thus the coal-black soils were not as common as areas in north-central Indiana.
Shingle oak is a slow grower can’t compete with most other species, other than other slow-growing oaks & hickories. For it to develop, it cannot be disrupted by more aggressive species growing underneath it & them around & over it. So intolerant to shade with age, the branches shaded by its own foliage frequently die & fall off the tree. There is a very narrow window for this tree to handle shade & that is in its first 2-5 years, generally & it usually only germinates in response to a sunny opening. In presettlement times, it was fires that did the job of prevent other more aggressive trees from competing with it. It can’t have such a fire regime to keep prairie prairie & it did best in presettlement barrens/savanna in a cyclical, semi-frequent or more occasional fire regime with prairies around it/nearby.
It seems to handle fire pretty well, especially low-growing fires. It will frequently re-sprout after fires as a small tree, but fires kill young seedlings. I have found that it is not as fire-hardy as Bur, Black or Post, or Blackjack Oak, but does as good, if not a hair better than White Oak.
Since it does not quite live as long as alot of our Indiana oaks, it must have thrived in a presettlement landscape environment of flux on the pretty rich, not too wet soils that it loves. What I mean, it that if the Shingle oaks in a savanna are dying because they are 170 years old & fall, but the huge White oaks live to 400, they will take over more than the Shingle Oak. That said, open environments with no closed canopy & borders allowed this species to go. In the world of vegetation dynamics in presettlement there are so many things going to determine where populations of species set up, for sure!
In that Illinoian Till Plain area of west-central & southwest Indiana, it reached & still reaches its greatest occurrence on those loamy/clayey soils of till plains & the rolling landscapes & bevels of the region. It also likes the wind-blown sandy soils of that region of Indiana. In the oak-hickory woods of the Driftless region of southwest Indiana, it likes the upland black oak woods & then also grows on the higher flatwoods of Post Oak in far southwest Indiana.
Shingle oak can also be found in our viewing area, especially in areas ringing the historic Grand Prairie region. It was most likely found in savanna/barrens bordering solid prairies. It probably reaches its second greatest occurrence in our viewing area & third greatest occurrence in the sandy soils & clayey soils of historically Black Oak & Black Oak/Northern Pin Oak barrens from Fulton to Kosciusko, Marshall, Elkhart to Allen counties.
Scattered pockets of the species exists as far east at Tipton to Huntington counties, but the trees is pretty rare or uncommon in the rest of the state.
Every species has its place in the sun, but Shingle oak is one of my favorite native species. It has nice form, those unique, leathery leaves, I like the dry winter foliage that hisses in the cold winter winds & fall color can be maroon, purple to red & burn orange. Its form is a lot like a Pin Oak, just not quite as triangular/pyramidal. There is a long-standing saying that it is time to plant corn & green beans once all of the Shingle Oak leaves (& beech leaves) have totally fallen off in spring. My grandfather Evans always told me that & it was pretty accurate! Young trees are usually clothed in dry, brown foliage in the winter, but the larger the trees, the less leaves it tends to hold. Frequently large, old trees may just have a small skirt of leaves on the lowest branches.
Squirrels & birds really like the acorns. They are sweeter than a lot of the Black Oak group members, which have a tendency of being bitter. Animals bury the acorns everywhere & since they greatly dislike competition & need total sun, sprouting next to a southside part of a home or next to a drain or stump is ideal for it to thrive.
Shingle oak doesn’t live as many other oaks & tends to hollow-out with age & eventually topple. A Shingle oak that split back home in an uncut barrens grove in our city park fell in 2001. The tree was not yet hollow & the rings showed the tree was a small seedling in 1870, but some of the Post Oaks & a White Oak in the park date back to 1825 as shrubby small trees in a barrens/prairie (now they are huge trees with fat trunks!).
Shingle oak is gaining popularity as a landscape & street tree & rightfully so. Several are planted along Cumberland Avenue by Applebee’s & Wal-Mart in West Lafayette. It is a slow grower, but worth it, if you can tolerate its self-pruning of its dead branches as it gets older.
Images of native oak barrens/savannas:
OVERCUP OAK (Quercus lyrata)
Also known as Swamp Post Oak, Overcup Oak is a swamp-loving species native to mainly southwestern Indiana with a few trees natively growing up the Muscatauck River swamps as far north as Washington & Jackson counties in Indiana. It likes consistently wet to submerged feet & is the tree of low, moving, widing, sluggish, silt-laiden southern river systems. This tree is a substantial component of the baldcypress & water tupelo (often festooned with Spanish Moss) swamps of the southern U.S. It likes tight, clayey soils of floodplains, oxbows and ponded flats that are very poorly-drained. It often had a buttressed base to hold the large tree up in soupy, mud environments, like a bowling pin.
Overcup Oak is highly-tolerant of flooding. I have seen it growing in environments flooded for months at a time, but like Baldcypress, bare soil or at least soil with only 1-2″ of water is required for seedling emergence. This rapidly occurs in fall after the acorns fall during Indian summer when swamps & wet areas are usually the driest for any time of year, on average. This is also an adaptive trait to germinate as rapidly as possible, as the acorns are consumed by animals. The small seedlings go dormant by November, then resume growth in spring. If seeds to not germinate in fall, they are very resilient in swamp conditions & may still be viable come spring after mid-winter high water transports the acorns to other sites.
A problem for seedlings is floods in the first few years. They really need 2-3 years without deep flooding to survive, so like Baldcypress, often times nice Overcup Oak reproduction & seedling/sapling establishment occurs during significant droughts. I have seen this first hand at Twin Swamps Nature Preserve in Posey County, Indiana, very close to where the Wabash & Ohio Rivers meet in far southwest Indiana. In an Overcup Oak swamp in the preserve, I observed mats of thousands of Overcup seedlings germinating during a droughty fall several years back. There were no other Overcup seedlings or saplings amidst large Overcup Oak trees, indicating that conditions had not been sufficient for Overcup germination & establishment in the previous years. These thousands of seedlings occurred in large openings of the forest, which brings up another good point. Overcup Oak really needs openings in the forest to regenerate, as the seedlings may sprout in shade, but must have a good amount of sun or they will not make it.
The species’ name refers to the corky, light cap around the acorn, which makes identification easly. This thin, corky layer serves as an important seed dispersing mechanism, as it acts as natural “floaties” so the acorn will float & “swim” in flood water. Acorns transported in this manner will germinate on a suitable site. A nice tap root may first be established by the tree, but it quickly roots laterally into a maze of shallow, fibrous roots. In its swampy habitat, this rooting habit is typical of the tight, poorly-drained soils of its habitat. This does make it seem more vulnerable to topple from storms, but the afformentioned buttressed base usually makes up for this issue.
On better sites than the swamps, the tree is easily crowded out by more aggressive Sweetgum, Cherrybark Oak, Swamp White Oak, etc. A slow-grower, this tree may take decades to produce acorns. Similarly-shaped to White & Post Oak, it has a nice, open, broad branching habit that makes it a nice specimen when older & in an open situation. Its bark is like Post Oak & its foliage superficially resembles Post Oak/White Oak combination.
In Indiana, it grows in groups, not large areas, along rivers & creeks of the southern bottomland region of southwestern Indiana. Several populations in Jackson, Washington, Scott & Clark County are northern appendages up the Muscatatuck bottoms from a population along the Ohio River at Louisville. At Twin Swamp Nature Preserve in Posey County, west of Evansville, the species was associated with Swamp Cottonwood & nearby Baldcypress. At the Patoka National Wildlife Refuge, in eastern Gibson County, Overcup Oak was growing with Sweetgum, Swamp Cottonwood, Pumpkin Ash & Swamp Chestnut Oak. North of Montgomery in Daviess County, Overcup Oak made up a significant percentage (~60%) of a woods near Prairie Creek with the other 40% largely Swamp Chestnut Oak. In western Daviess County, near Swan Pond, in the East Fork White River bottoms, the species was found growing with Silver Maple, Sweetgum, Black Willow & Swamp Cottonwood. The Vanderburgh County bayou woods off U.S. 41 & I-164 yielded Overcup Oak, Silver Maple, Cherrybark Oak, Baldcypress, Pecan & American Elm. The northernmost trees are said to exist in western Sullivan County, Indiana, but I have not searched, nor had permission to search for the species there.
Jackson-Washington State Forest yields excellent bottomland/swamp oak forest with stands of Pin, Swamp White, Swamp Chestnut & Overcup Oak in Jackson & Washington counties. Thomastown Bottoms Nature Preserve in Scott County also yields some Overcup Oak. Like all other Overcup Oak in the state, though, it is not widespread & trees tend to occur in colonies.
Migration of Overcup Oak has occurred in the past up the waterways & their bottoms of southern Indiana, which provide a great avenue for the tree to move north. The large swamps in southern Indiana as a result of water backing up trying to get into the Ohio & Wabash to Mississippi River at glacial melt, have provided appreciable habitat. The lake plains, low areas, slow-moving, not-easily-draining, widing rivers that just cannot expel water quickly with the laminated, tight, silty-clayey lake soils of the area helped Overcup oak become a native Indiana tree.
CHERRYBARK OAK (Quercus pagodaefolia)
No other area of the state does the rich bottomland oak & oak swamp forest reach a creshendo like those lake plains & river/stream bottoms of southwest Indiana. Dominated by swamps more reminiscent of the southern U.S. & wet oak forests like those of the Lower Mississippi region, southern earmarks in the flora appear in these areas. Here you see native Baldcypress, mistletoe, Winged Elm, Overcup Oak, Swamp Chestnut Oak & others that are strictly southern U.S. flora. The streams in this part of Indiana are typically slow-flowing, prone to long, murky, silty floods & water backing up, where low, wet woodland is common. This is the domain of Cherrybark Oak. A large, massive, long-lived species, with greatest development in the state in Posey & Vanderburgh counties, this tree usually grows in the company of other bottomland oaks (specifically more southern oak species), like Swamp Chestnut, Shumard, Post (Delta Post Oak variety & genotypes) as well as our more frequent Swamp White & Pin Oak (the larger type closely associated with var. mississippiens). It likes the low, wet woodland which has ponding occasionally, where it grows it has a close association with sweetgum. It also likes the bottoms near rivers in general that do not flood really deeply, but for shorter periods, in a more shallow manner & likes wetter locations than its close relative the Southern Red Oak (Quercus falcata).
Interestingly, I have found some Cherrybark in the rich coves of hills of deep yellow-brown silty loess with tuliptree, sweetgum & black walnut in its Indiana range. I especially found this across the Ohio at Audobon State Park in Henderson, Kentucky, where Cherrybark, tuliptree, sweetgum & American beech were found mixed together. The higher ridges of the park had Southern Red, Black, White oaks, Shagbark & Mockernut hickories with tuliptree & white ash. It appears the species may creep up coves off river bottoms to these pockets.
Cherrybark Oak is named for its bark, which resembles Black Cherry & its Latin species name pagodaefolia refers to the leaves, which resemble Chinese pagodas when turned upside down. Also called Swamp Spanish Oak, named after Spanish Oak, another name for Southern Red Oak. This tree is a beautiful one in shape, foliage & fall color. That said, it is becoming increasingly available in the nursery trade each year. I just noticed a garden center in West Lafayette just received a shipment of Cherrybark Oaks. It seems to have decent tolerance for colder climates north of its native range & with rapid growth, I think you will see more & more of Cherrybark Oak planted in Indiana. It is a good alternative to Northern Red Oak & Pin Oak. Like Willow Oak, it is becoming more of a star in the garden trade outside of the southern U.S.
Wind blowing through Cherrybark Oak foliage is beautiful. The undersides of the leaves are covered in white downy fur & the upper leaf sides are shiny dark forest green. The wind makes a shimmering appearance with the foliage with the contrasting colors & the finer foliage (compared to Northern Red Oak) looks better. Leaves often turn maroon, scarlet & red in autumn, while younger trees & the lower limbs of larger trees retain dry, brown winter foliage. Despite it bottomland & flatwoods habitat, it is adaptable to urban environments & subdivision planting.
Needing openings to re-generate, this tree can only tolerate partial shade for the first few years as a seedling & sapling, then must have lots of sun to survive. The species is very vulnerable to withthrow, having a shallow rooting habit, which ironically opens up the forest to new Cherrybarks. Cherrybark Oak has a very competitive relationship with its closest associate, the Sweetgum. It has to compete with the more aggressive Sweetgum. According the the U.S. Forest Service, an acid is leached from the leaves with rainfall that suppresses Sweetgum growth.
Found usually as scattered individuals or in groups in its native habitat, it is occasionally very common in a stand (usually with Sweetgum). I found this in Posey & Vanderburgh County near the Ohio River in bottomland forests. Growing on those rich, low bottomland soils, Cherrybark Oak has been a real victim of land clearance for agriculture. In Vanderburgh County, in a sea of farmland of the Ohio River bottom, I found scattered large trees in the middle of the vast farmland, remnants of the bottomland forest. Considered one of the best of the red oaks, this tree is an extremely important timber trees in the Lower Mississippi area & Mississippi Delta region, where Northern Red Oak does not exist. Forest trees have long, clear boles with trees reaching 150′ in height. The trunk may be clear of branches for the first 90′.
COMMON HOPTREE (Ptelea trifoliata)
Most are not familiar with this species of this small understory floodplain & low woods, often near streams, rivers & lakes. A native Hoosier member of the Citrus family, it is sort of an odd ball species with leaves that look like poison-ivy & interesting, papery & circular seeds, like Rock & Slipper Elm, but larger. With nicknames of Wafer Ash, Skunkbush (its flowers, wood & bark have an unpleasant odor) & Prairie grub, it doesn’t get too large at 30′ with a diameter of 1′ underneath much bigger trees. Liking the same habitat as Ashleaf Maple (Boxelder), Black Maple, Ohio Buckeye, American Sycamore & Black Willow, it may prefer the understory of low woods, but can be found in full sun, too on swamp borders & near lake sides. An example are the hoptrees growing at Celery Bog near the trail by the apartments at the end of Cumberland Avenue. Here, it grows with Black Willow, Green Ash & Rose Mallow, as well as Swamp Milkweed. In the understory it may be crooked with one trunk, but trees more in the sun often have multiple trunks.
The most common associates of Common Hoptree are Black Willow, American Sycamore, Silver Maple, Green Ash, Ashleaf Maple, Eastern Cottonwood, Buttonbush, Black Walnut & American Elm. In far southern Indiana, you can find it with Cherrybark Oak & Sweetgum, as well as Swamp Privet. So, it can tolerate periodic, but not long, long duration flooding & germinates on fresh floodplain loam of the understory woods in shade or sun. It has impressive flood depth tolerance, similar to Ashleaf Maple, Silver Maple & American Sycamore. Like Silver Maple, it doesn’t mind a deep flood, it just can’t have constant, consistent standing water. That is an oddity about Silver Maple, it tolerates floods well, but if it will struggle big time if it is growing in a long-duration submergence event as a young tree & even older one. I have seen Silver Maples all wilted, half dead & with red & orange foliage in summer when stuck in tight clay soil with standing water. Ohio Buckeye likes brief floods in loamy/sandy loam floodplain soil & low, wet woodland, but doesn’t like persistent inundation & saturation. Common Hoptree is no different.
Leaves of the hoptree turn often yellow in the fall & occasionally red & orange.
A slow-grower, this tree blooms in late spring-early summer & sheds its seeds through late fall & into winter. Frequently, the papery seeds will cling to the tree well after the foliage has been shed in fall. The seeds are carried by wind on its papery “wings”.
There are several subspecies of Common Hoptree in the United States. Ours, which is found viewing area-wide is found strictly in the historic prairie/barrens band from Missouri to Illinois, Indiana & Ohio to southeastern Ontario. This subspecies does have an affinity for the low, wet woodland near/around prairies, savannas & barrens.
About 5 other subspecies are found in the U.S. One from Arizona to Mexico to Texas, another Texas to Kansas, another in the southeastern, even another in Florida.