Big Tree Hunt, Part 1: The Bald Cypress

Who doesn't love a big, beautiful tree? Those venerable neighbors who have inhabited our land for dozens, if not hundreds, of years, eluding the inexorable advance of both plow and bulldozer. Do you ever look at a massive trunk topped by a beautiful spreading crown and think, "That must be the biggest tree in the state!"?

Good news! Iowa has a "Big Tree" program that documents state champions of different species. What makes a champion? Trees are measured using three dimensions: height, crown spread, and trunk circumference. Those dimensions go into a formula that assigns a points value to the tree. The trees that have been documented with the highest point totals in each species can be found in a list published by the DNR. Although the program is technically under the aegis of the DNR, it relies on volunteers to do the heavy lifting, particularly one amazing and dedicated volunteer by the name of Mark Rouw. 

Iowa City boasts a number of champion trees, including a Hophornbeam in Hickory Hill Park, as well as several specimens on the University of Iowa campus featuring the state champion Black Walnut on the Pentacrest. (If you enjoy trees, be sure to explore the UI Campus Arboretum and its tree inventory map.)

The Sycamore Greenway doesn't have a lot of big trees (yet...check back in a few decades!). Like much of the state, it is a developed or constructed area and thus very "young" in terms of tree life. When I went in search of the champions of one of my favorites, the Bald Cypress, I discovered a treasure of big trees in an old river town just a day trip away.

Burlington, Iowa, is famous for Snake Alley, its crazy twisting brick road. But it also home of many champion trees, a significant number of which have escaped that plow and bulldozer by virtue of making their homes in a venerable cemetery and a spectacular city park, both of which were established well over a century ago. I set out, with much enthusiasm and very little plan, to visit some of those arboreal elders.

Pulling into Aspen Grove Cemetery and confronted with a spider web of narrow, winding roads and paths, that lack of plan was immediately apparent. My target was the #2 state champion Bald Cypress, the only one of its kind on the list with a location provided (the others apparently on private property). It was 84 feet high with a trunk circumference of around 11.5 feet.* How hard could it be to find a beautiful Bald Cypress that size? 

Well. 

First off, the cemetery itself is spectacular. Established in 1843, three years before Iowa became a state, and listed on the National Register of Historic Places, it is the final resting place of Aldo Leopold as well as many U.S. Representatives from the late 19th century. It also sprawls over 133 acres as the paths meander up and down hills, criss-crossing with named roads that would perhaps be helpful to someone who had an idea of where they were going. 

Alas, under the "Location of Tree" column on the Big Trees spreadsheet, it said only "Low ground, Aspen Grove Cem. Burlington, Des Moines Co." So after turning in the direction that seemed headed downhill every time I reached an intersection, unsure of whether I had wandered into an access road or somewhere else I wasn't supposed to be and attempting to behave in a respectful manner...there it was! Was it? 

To be perfectly honest...I don't know. It was a big, beautiful Bald Cypress and it seemed to be nestled in a sheltered depression, near a curious deep canal that lent an eerie and ancient atmosphere with the low, misty morning chill in the air. 

The spreading branches still held many of their leaves in early November, though a glowy russet color had replaced the soft summertime green. Below the branches a soft carpet of fallen leaves (needles? Some sources describe them as needles; some as leaves. Others split the difference and use "needlelike leaves) rest undisturbed. 

There on consecrated ground, with this living thing that had stood sentinel for decades as the town grew and faded and individual human lives came into and passed out of this earth...can an experience be mildly transcendent? 

But alas, my schedule did not include unlimited hours to commune with a tree, no matter how enthralling. The cemetery is home to other champions, including a Mockernut Hickory, Flowering Dogwood, and White Ash. But time being limited, I had to make my way to Burlington's other refuge for amazing trees: Crapo Park.  

To be continued....

*For comparison, the national champion Bald Cypress in Louisiana is just a bit taller, at 91 feet, though it has an impressive crown spread of 87 feet and its trunk measures a whopping 52 feet around.

Read more about Iowa's Big Trees:

• https://www.southeastiowaunion.com/environment-nature/iowas-big-trees-valuable-for-education-vulnerable-to-vandalism/
• https://www.inhf.org/blog/blog/chasing-champions/

Behind the Fence

On the north side of an impenetrable white vinyl fence, unseen and likely forgotten by those who built the fence, a little micro-habitat of opportunists thrives just out of reach of the trailside mower. 

Horseweeds, sowthistles, fleabane, dock, amaranth, a spiky flatsedge, and an enterprising grapevine are just a smattering of the dozens of plants making a community in this shady, 65-foot span. Even late in the season, into October, there were still some flowers available on the horseweeds and fleabane to bring an assortment of tiny pollinators, including a stunningly-patterned moth. 

Spotted Beet Webworm Moth

(Hymenia perspectalis, tentative)

Earlier in the season, this scrappy little patch would have barely merited a glance, when just opposite the Greenway was glowing with big, beautiful flowers everywhere. But squeezing out the last bits of summer, before the last flowers fade and the last insects disappear for the long winter months, it's a low-expectation oasis. 

Life happens when we give it a chance. 

 

Consider the Spider

Orchard Orbweaver

"Once you begin watching spiders, you haven't time for much else."

- E.B. White

Consider the spider. Eight legs, eight eyes, silken webs. When welcomed into the home, may go by the name of Charlotte or Boris. Everyone has an idea of what "spider" means. 

Bowl and Doily Spider (tentative)

But do we? Records on iNaturalist show more than 60 species of spider identified in Iowa City alone; though they share a similar general body shape, there is an astonishing variety of features that can be seen, with different groups adapted to different lifestyles. They are generally divided into two categories: those that spin webs, and those that hunt their prey. 

Within those two categories there are dozens of other specializations. Some species of web-building spiders may create the typical two-dimensional spiraling orb between vertical branches or posts, like the beautiful jewel-toned Orchard Orbweaver; others make those cobwebs that add atmosphere to the corners of your basement, or they construct elaborate sheets (or even "bowls and doilies")  held aloft on grass stems.

Hunting spiders are further categorized as wolf spiders, jumping spiders, crab spiders, and several others. They may still produce silk, as a dragline to help them get around, for example, but they don't create webs to trap their prey. Nimble jumping spiders actively hunt with the help of their excellent eyesight, while many crab spiders rely on camouflage to lurk in wait for a passing insect.

They are beautiful, beguiling little bits of life that share our yards, and sometimes our homes. They feature in our stories and our songs, and are worth spending time getting to know. 

Sources/Additional Reading:

• Common Spiders in and Around Homes - ISU Extension (PDF)
• Spiders - University of Minnesota Extension

A pair of domestic spiders(?) found around the house:

Bold Jumping Spider

Common Cellar Spider

The Not-so-subtle Senna

Yellow, yellow flowers everywhere. Walking a familiar part of the trail, my eyes scan the usual floral sights of late July: the Silphium brothers Cup Plant (big brother) and Rosinweed (little brother); inspecting the Gray-headed Coneflowers for Camouflaged Loopers...hello, what's this?

My brain, seeing the shape and color of the bushy yellow inflorescence, quickly said "Showy Goldenrod, nothing unusual, move along" followed immediately by "isn't it a little early for goldenrod?" and directing the eyes back for a closer look. 

Bees and ants visiting
senna flowers.

Despite the initial vague resemblance...definitely not a goldenrod. For one thing, the leaves are compound, with tidy paired leaflets. And the yellow flowers comprising the showy inflorescence were big and blowsy, with many dark anthers projecting from the loosely open petals. A senna! Has that been there all these years and I've just never noticed it before now? It's hardly a subtle plant.

There are two similar species of senna in our area, which can be tricky to tell apart: Maryland Senna (Senna marilandica) and American or Wild Senna (Senna hebecarpa). Some points mentioned to help identify are the hairiness of the style (longer on Wild Senna) and the behavior of the seedpods. (I am not confident in our senna here so I will just call it a senna.) 

Knob-like nectaries are situated
at the base of leaves.

They are members of the legume family and are native to the eastern U.S., with Maryland Senna having a slightly wider range, reaching Nebraska and points south. All those stamens (ten in total) provide pollen to bumble bees (and many other pollinators). 

If you look closely at the base of the leaves, you'll find a curious rounded knob: an extrafloral nectary, which makes sweet nectar available to ants, wasps, ladybird beetles, and other insects that may take advantage of the nourishment, possibly providing protective services to the plant in exchange. (Another yellow-flowered native legume, Partridge Pea, similarly provides nectar in the form of little pots at the base of the leaves.)

It's a beautiful plant, and provides a lot of interest not only to wildlife but human observers too. I'll definitely be keeping an eye out for it in the future. 

Really...not very subtle.

Sources/Additional Reading:

• Plants For Pollinators: Wild Senna
• ‘Will Work for Food’ – Extrafloral Nectaries
• USDA Plant Fact Sheet: Wild Senna
• Illinois Wildflowers: Wild Senna and Maryland Senna
• BONAP
• North Carolina Extension: Senna marilandica
• Friends of the Wildflower Garden: Wild Senna

Ratibida Reverie

Today we're taking a field trip about a mile due west of the Greenway, to Terry Trueblood Recreation Area, where you might encounter a few small patches of Ratibida columnifera, known variously as Mexican Hat, Upright (or Longheaded) Coneflower, and Prairie Coneflower—the second of only two species of Ratibida found in our area (and only four found in the entire U.S.).

While the Gray-headed Coneflower (R. pinnata) is native to the tallgrass prairie and widespread throughout Iowa, its low-growing cousin actually hails from out west in the Great Plains, with only the eastern edge of its range just reaching western Iowa. It is adapted to drier conditions than R. pinnata and probably finds the sandy area around TTRA more amendable than the Greenway's moist soils.

You can tell the two species apart by the shape of the flowers (although the photo above and at right is a slightly stunted specimen): R. columnifera's "cones" are usually longer than its wide yellow petals, whereas R. pinnata's yellow petals are longer and thinner beneath a shorter, more rounded "cone". 

Left: Ratibida columnifera. Right: R. pinnata

The leaves and growth habits reflect the habitat preferences of each plant as well: R. columnifera's skinny, hairy leaves help minimize water loss and exposure to the hot sun; R. pinnata's leaves are wider and while also a bit hairy, not as densely so. And much as the prairie transitions from the tallgrass in the east, with its abundant moisture, to shortgrass in the arid west, the tallgrass species Ratibida pinnata can reach 4-5 feet tall while R. columnifera tops out around 3 feet. 

Mexican Hat comes in different forms: its petals may be solid yellow, solid dark red, or dark red with yellow at the edges. Given its natural range, those individuals you find in our area are likely planted specimens from a seed mix or as garden ornamentals. They can be visited by bees, butterflies, and other insects, similar to Gray-headed Coneflower.

Cultivated R. columnifera (from the author's garden)

Sources/Additional Reading:

• http://www.illinoiswildflowers.info/prairie/plantx/mexican_hat.htm
• https://bonap.net/Napa/TaxonMaps/Genus/County/Ratibida
• Midewin National Tallgrass Prairie - Resource Management (usda.gov)

Fantastic Floristic Features at Corriell Preserve

The sand prairie at Corriell Preserve

This past weekend, Bur Oak Land Trust offered a glimpse of Corriell Nature Preserve (normally not open to the public) to visitors for Blooming Cactus Weekend. Although the stunning yellow cactus flowers on the sand prairie were a highlight, a special treat was a guided tour with Dr. Thomas Rosburg of Drake University, to talk about the floristic survey he is conducting at the site. 

Katydid nymph

Attendees were given a list of the more than 300 plant species Dr. Rosburg had documented so far, and a hike through the preserve provided the opportunity for both Dr. Rosburg and Jason Taylor, Executive Director of Bur Oak Land Trust, to share information about plants of interest, the history and current state of the site, as well as how a floristic survey is conducted.

Describing the species present at any location--much less almost 200 acres of diverse habitats including wetlands, forests, sand prairie, and pasture grassland--takes multiple visits over the course of the growing season and over multiple years. Because different plants may be more or less conspicuous at different points in their growth, visits from early spring through summer and into fall are necessary to capture the widest variety of species possible. Conditions may change from year to year as well; Dr. Rosburg told of a pond, full of water this year, that was much drier a previous year, allowing access to plants that may otherwise be inaccessible. 

It is impossible to summarize all of the information provided during the hike, so I will limit this post to sharing some of the plants we encountered and strongly encouraging you to both visit Corriell Preserve when the opportunity next arises, as well as find and attend a similar event with Dr. Rosburg! Be sure to follow the Iowa Native Plant Society to learn about future opportunities.

Grasses, Sedges and Rushes

There were many sedges and rushes, normally very easy to overlook, pointed out by Dr. Rosburg.

Gray's Sedge

Davis Sedge

Great Plains Flat Sedge

Great Plains Flat Sedge

Schweinitz's Flatsedge

Dudley's Rush

Scribner's Panic Grass

Forbs

Some spectacular, some subtle...an amazing variety of flora.

Wild Senna

Western Ragweed

Virginia Plantain

Virginia Plantain

Carolina Geranium

Wild Petunia

A single large Butterfly Milkweed was
crawling with pollinators.

Prairie Rose

Prairie Larkspur flowers,
a little past their prime.

Prairie Larkspur foliage.

Sleepy Catchfly. The red stripes on the stems are sticky.

Green Milkweed

Ladybird, ladybird

Polished Lady Beetle
(Cycloneda munda)

Cicadas may be the trendy insect this summer, but ladybugs have a special place in many people's hearts. Their rotund form, bright colors, and simple patterns make them easy for even children to pick out in a crowd. Generally pictured as shiny, round, red beetles with black spots on their hard forewings (elytra), ladybugs can actually come in various colors and may have many or no spots at all. Some may even have stripes! Their pronotum (the shield-like structure behind their head) has different patterns, often in black and white, that can be useful to help identify different species.

(The common name "ladybug" is convenient and will be used here, though technically only around half of all ladybugs are "ladies" and none of them are true "bugs" in an entomological sense. They are more properly called "ladybird beetles" or "lady beetles.")

Convergent Lady Beetle
(Hippodamia convergens)

BugGuide notes a total of 81 species occurring in Iowa. iNaturalist shows more than 20 different species of lady beetles spotted in Iowa, with the most popular by far being the non-native Asian Lady Beetle (Harmonia axyridis), possibly due to its habit of overwintering in human homes making them more visible than other species, which may overwinter in sheltered places such as under rocks or bark, or in leaf litter or protected snags. Ladybugs will overwinter as adults, sometimes in groups.

Like butterflies and bees, ladybugs are holometabolous, meaning they undergo complete metamorphosis from their larval stage to adulthood, with a pupal stage in between. Ladybug larvae are often described as "alligator-like": long, segmented, and spiky, often sporting similar red-and-black coloration to the adults but otherwise little resembling their future selves. Both larvae and adults eat aphids and other pest species, making them welcome visitors for gardeners. 

The bright red and black elytra of many species are an example of aposematic coloration, warning potential predators that their potential meal may be toxic (or at least have a foul taste). Nevertheless, ladybugs may be preyed upon by frogs, birds, spiders, and other insects including dragonflies and ants. 

Seven-spotted Lady Beetle
(Coccinella septempunctata)

Although many species of ladybugs are common, a few have experienced drastic declines in their populations in recent decades. The Lost Ladybug Project is a citizen science program that attempts to document the Nine-spotted Lady Beetle (Coccinella novemnotata) as well as the Two-spotted Lady Beetle (Adalia bipunctata), both of which are thought to be vexed by the common refrain of habitat loss combined with competition from introduced species (including the common Seven-spotted Lady Beetle pictured at right). 

All the ladybugs pictured here were spotted over the course of an hour along the Greenway one recent sunny day. 

Ladybug larva with aphids

Sources/Additional Reading:

• Lost Ladybug Project
• Bug Guide: Family Coccinellidae
• Cornell University - Biological Control: Lady Beetles
• Xerces Society: Nine-spotted Lady Beetle
• University of Minnesota Extension: Lady beetles