Friday, November 7, 2014

Ramble Report November 6 2014


Twenty-three Ramblers assembled at the Arbor by the Lower Parking Lot  for a Ramble on Grasses led by Linda Chafin.

Don Hunter's photo album for today's ramble is here.

Event of Interest: Doug Tallamy, author of Bringing Nature Home is speaking at the Exotic Pest Plant Conference at the Georgia Center, Nov 12 and 13, 3:50pm. Admission is $15.00 for each presentation.

Today's readings: Today we had readings brought to us by Ed Wilde, Hugh Nourse and Linda Chafin.

Ed Wilde summarized his reading on using your backyard to conserve the environment from Bringing Nature Home by Doug Tallamy (Timber Press, 2009):

Chances are, you have never thought of your garden - indeed, of all of the space on your property - as a wildlife preserve that represents the last chance we have for sustaining plants and animals that were once common throughout the U.S. But that is exactly the role our suburban landscapes are now playing and will play even more in the near future.
If this is news to you, it's not your fault. We were taught from childhood that gardens are for beauty; they are a chance to express our artistic talents, to have fun with and relax in. And, whether we like it or not, the way we landscape our properties is taken by our neighbors as a statement of our wealth and social status. But no one has taught us that we have forced the plants and animals that evolved in North America (our nation's biodiversity) to depend more and more on human-dominated landscapes for their continued existence.
We have turned 54% of the lower 48 states into cities and suburbs, and 41 % more into various forms of agriculture. Humans have taken 95% of nature and made in unnatural.
Once common species such as the northern bobwhite, eastern meadowlark, field sparrow, and grasshopper sparrow have declined dramatically in total numbers, and are completely absent from many areas that used to support healthy populations. The pressures on wildlife populations today are greater than they have ever been and many gardeners assume they can remedy this situation by simply planting a variety of flowering perennials, trees, and shrubs.
What will it take to give our local animals what they need to survive and reproduce on our properties? NATIVE PLANTS, and lots of them. There is an unbreakable link between native plant species and native wildlife. Indeed, most native insects cannot, or will not, eat alien plants. When native plant species disappear or are replaced by alien exotics, the insects disappear, thus impoverishing the food source of birds and other animals. So many animals depend on insects for food (e.g., spiders, reptiles and amphibians, rodents, 96% of all terrestrial birds) that removing insects from an ecosystem spells its doom.
We have planted Kousa dogwood, a species from China that supports no insect herbivores, instead of our native flowering dogwood (Comus florida) that supports 117 species of moths and butterflies alone.


By way of introduction, Hugh read the first paragraph of Linda Chafin’s latest article, ID’ing Grasses for Beginners, in Tipularia (2014), p. 14.:

If I had a dollar for every time I’ve said “I don’t do grasses…” over the last 30 years, I could retire – to some fabulous place on the planet where there are no grasses to do. But, wait – there is no place on our planet without grasses and if there were, it sure wouldn’t be fabulous: an environment without grasses would be a sad and impoverished place. Plus there wouldn’t be much of anything to eat!

Then Linda read a poem by Veronica Patterson, reflecting on what to do after Tuesday’s election:


A Charm Against the Language of Politics
Say over and over the names of things,
the clean nouns: weeping birch, bloodstone, tanager,
Banshee damask rose. Read field guides, atlases,
gravestones. At the store, bless each apple
by kind: McIntosh, Winesap, Delicious, Jonathan.
Enunciate the vegetables and herbs: okra, calendula.

Go deeper into the terms of some small landscape:
spiders, for example. Then, after a speech on
compromising the environment for technology,
recite the tough, silky structure of webs:
tropical stick, ladder web, mesh web, filmy dome, funnel,
trap door. When you have compared the candidates' slippery
platforms, chant the spiders: comb footed, round headed,
garden cross, feather legged, ogre faced, black widow.
Remember that most short verbs are ethical: hatch, grow,
spin, trap, eat. Dig deep, pronounce clearly, pull the words
in over your head. Hole up
for the duration.

(From The Sun, November 1992, issue 203.)

Today's route: Our ramble began at the Arbor and then proceeded down the walkway in the Shade Garden to the road, across the road, and up the white trail to the power line ROW.  We walked up the path through the Elaine Nash Piedmont Prairie.  At one point we turned around and walked down the hill to the service road to the Mimsie Lanier Center for the Study of Native Plants.  Then we returned to the Arbor.

The first stop had nothing to do with grasses.  A mockernut hickory nut husk split opened by a squirrel was found by Linda  on the walkway.  Linda suggested that the name mockernut comes from the toughness of the nut.  It is mocking those who try to get at the nut.  The tree with the typical cross or diamond shaped ridges in the bark was next to the walkway.

Note: Throughout this report we will insert the species accounts from Linda's recent Tipularia (the journal of the Georgia Botanical Society) paper: ID'ing Grasses for Beginners. The quoted material is in a different typeface.

Across the road, Linda stopped at the sedge that we have discussed before.  She recited the ditty: Sedges have edges, rushes are round, and grasses have knees all the way to the ground, and was also able to tell us that this mystery sedge is probably fragrant flat sedge.  (She also noted that not all sedges have edges. Plants do not read books.)

Witch grass
In the open area next to the sedge and very close to the ground was a rosette with extremely small flowers called witch grass in the genus Dichanthelium. 

Across the trail was a nice stand of river oats, or fish on a pole.



        
River Oats
River Oats (Chasmanthium latifolium) is a great grass to learn on. It grows in lots of natural areas in wet areas and on stream banks, and has been planted all over town, so it’s easy to find. Its parts are large, and they are all there. The flattened, inch-long spikelets dangle at the tips of long stalks in the summer and fall and are made up of 6 - 18 florets that overlap at the base, forming a distinctive herringbone pattern. Separate out one floret and pull back the lemma to find the pistil and stamen, or later in the year, a seed-like fruit called a grain, or an achene, or a caryopsis, depending on whose book you are using. If you are fortunate enough to live near the beach, you can do the same with Sea Oats (Uniola paniculata), the iconic grass of beach dunes and a close relative of River Oats. This salt-tolerant grass is one of the most ecologically important grasses in the southeast. Their deeply rooted stems preserve dunes during ordinary storms and high water, and provide a base for dune rebuilding after severe storms.


Next was broomsedge.

       
Broomsedge
Broomsedge Grass (Andropogon virginicus) is probably the most common and well known native grass in the South. I grew up calling it Broomsage, but it is neither a sage nor a sedge. It’s the grass that gives pastures, rights-of-way, and other dry uplands that coppery glow in the winter. Broomsedge culms are round, not 3-angled like sedges, and are 1 - 6 feet tall. Held at the top of the culm, the flower cluster has conspicuous leaf-like bracts called spathes. The spathe is longer than and partially encloses the spikelets. Spikelets are held on hairy stalks and the whole seed head has a hairy aspect to it. Both lemmas and glumes are awned, which adds to the hairy look. Bushy Broomsedge (A. glomeratus) is very similar but its flower clusters are more densely packed with larger spikelets, so the top of the culm looks thick and bushy. It occurs in low, wet areas.

Right beside it was splitbeard broomsedge:

Splitbeard Broomsedge
Splitbeard Broomsedge (Andropogon ternarius) is nearly as common as Broomsedge in disturbed habitats and, at 60 mph, looks much the same. Up close, though, it has several distinctive features. Its culms seem to be banded with broad stripes of red and green. Actually, the culm is red and the leaf sheaths are green. Splitbeard’s spikelets are not enclosed in a spathe like Broomsedge’s are. Instead, the hairy, heavily awned spikelets are in pairs at the tips of long, slender stalks. As they mature, the pair separates into two hairy parts, ultimately forming a conspicuous V-shape. The spikelets eventually break apart and disperse, leaving behind a little tuft of white hairs that looks like a heavily used paintbrush. Little Blue Stem, Schizachyrium scoparium, also has red and green banded culms, but it is a smaller plant with a single, sparsely flowered spikelet.

We walked into the Elaine Nash Piedmont Prairie named in honor of Elaine Nash.  Elaine was known in the Georgia Botanical Society as the Grass Lady.  Linda discussed how she had worked in a soil conservation agency and had noticed that no one knew much about grasses, so she taught herself, and became the expert in the State to go to for help in identifying grasses,  planning landscapes with grasses, and growing grass meadows or prairies. She was the expert that helped Panola Mountain convert a fescue pasture to a grassland and Sandy Creek Nature Center establish it’s grass pocket  prairie.  Linda herself was inspired by Elaine and began her own grass odyssey.

First was purpletop grass:

Purpletop
Purpletop or Greasy Grass (Tridens flavus) is another common roadside grass that flowers in the fall. Its large flower clusters have an open and airy look, with wiry, slightly drooping, widely spaced branches whorled around the culm. The spikelets are shiny red or purple and coated with a waxy substance. Grab the flower cluster and pull it through your hand – you’ll definitely understand the reason for the name Greasy Grass. The leaves are rough to the touch and less than ½ inch wide. The leaf collar has tufts of hairs where it meets the culm and the ligule is also a ring of hairs. Purpletop spikelets have all their parts so, just for practice, use your hand lens to locate the pair of glumes (one smaller than the other) and the two overlapping rows of lemmas. The genus name Tridens refers to the fact that three lines of hairs occur on the lower half of each lemma, letting you know that whoever named these plants had a very good microscope nearby.

Nearby was wild ryegrass:

Wild Rye
Eastern Wild-Rye (Elymus virginicus) is another common grass of moist forests and bottomlands with easy-to-see parts. Wild-Ryes are cool season grasses, but the seed head of this species can often be found, dry and tan, in the summer or fall. Its fresh seedheads are erect spikes up to 6 inches high. There are several distinctive features of Eastern Wild Rye. Its lemmas and glumes have long awns, so the whole seed head looks bristly. Its hard, pale glumes bow out at the base, forming a U-shape. The leaf nodes are swollen and usually coated with a waxy, white, powdery substance called (confusingly) bloom. And the whole plant, when fresh, is a lovely, grayish-green color.

We went off the path toward a silver plume grass, but before we could get there we found a spring flowering witchgrass related to the first rosette we saw.  Also on the way was big top lovegrass.  This plant is 60 to 120 cm tall with densely long hairy stems (culms).  The head of the plant has many horizontal branches, not drooping like purpletop grass.  Then we reached the silver plume grass.

Silver Plume grass and Ramblers


Silver Plume Grass (Saccharum alopecuroides) is one of our tallest grasses, up to 10 feet tall. It is conspicuous on road banks and in other dry disturbed areas in north Georgia. Its stout culms are crowned by a large, showy seed head packed with hundreds of spikelets. As the seed head expands in late summer, it turns a silvery, pinkish-purple color. After blooming, it becomes a white and woolly plume. Each spikelet is covered with long hairs and the lemmas are awned with long, spirally twisted bristles. Its leaves are up to 2½ feet long and 1 inch wide with a conspicuous white midvein. Pull back the blade and look at the fringed, ¼ - inch high ligule. Sugarcane Plume Grass (S. giganteum) occurs in wetlands and wet ditches, mostly in the Coastal Plain, and grows to 13 feet tall. Its awns are straight, not spirally twisted.

Linda did discuss the white mid vein on the leaf as not a very good diagnostic feature because it appears on other grasses such as Johnson grass, as well as other grasses.   This gave her a chance to discuss Johnson grass:

Johnson Grass (Sorghum halepense) is an exotic species that has invaded roadsides, pastures, and other clearings. It is a large, coarse grass and, once you know it, it is easy to spot at 60 mph. Johnson Grass has the distinction of being one of the worst pest plants in the world and is resistant to glyphosate (aka Roundup), which is very bad news for farmers. Its leaves are large, up to 3 feet long and 1½ inches wide. Running the length of the leaf blade is a thick, white midvein – it is slightly off center and gives a satisfying snap if you bend the blade in two. (Since this is an exotic pest plant, feel free to maul as many leaves as you’d like!) Pull the leaf blade away from the stem and look for the ligule at the top of the sheath:  it consists of a fringe of ¼ - inch long, silvery hairs. Johnson Grass flowers in the fall, and its large, much branched flower clusters are purple or dull red. If you have a good hand lens or dissecting microscope, look at the spikelets. You will see that they are in pairs or in 3’s. One spikelet of the group has no stalk, and the other 1 or 2 are on tiny stalks. The glumes are hard, shiny, and reddish.

We did ooh and aah over the late purple aster by the silver plume grass.  Someone asked if it was Georgia aster.  It was not, and we were to see the difference when we found several at the Mimsie Lanier Center.

As we moved back toward the walkway several new grasses were found.  One was black needlegrass which has long needle awns projecting from the terminal spikelet. 

Black Needle Grass (Piptochaetium avenaceum) is a cool season grass found in upland woods, especially around granite outcrops. Its leaves are long and wiry, and the ligule is a delicate, transparent tube. The foot-long flower cluster is open and airy with long, wiry, nodding branches. The spikelets are black, and each has a set of short barbs at its base and a long, spirally twisted awn at its tip. Once the seed is mature and the spikelets are shed, the awn reacts to changes in humidity by twisting and untwisting, boring the seed into the ground; the barbs secure the seed in place. You have to admit: seed dispersal strategies don’t get much cooler than that.

Beaked panicgrass
Nearby was beaked panicgrass.  I remember looking through the hand lens to see the beaks on the seeds. Arrow
Threeawn grass
feather threeawn grass was next. The three awns (bristles) seemed to go all the way up the stem. The leaves were curly.

Here we turned around and headed down the hill to the road to the Mimsie Lanier Center.  Along the way we found a tulip tree samara.  Beside the walkway was an exciting find, yellow foxtail grass and small foxtail grass:

Yellow and Small foxtail grasses
Foxtail Grasses (Setaria spp.) are a group of easy-to-recognize grasses found throughout Georgia in many kinds of habitats. They range in size from a few inches to 20 feet tall, but they all have a distinctive seed head: cylinder-shaped and densely packed with spikelets that radiate out from the axis. The seedheads are very bristly and, in this case, the bristles really are bristles (meaning they arise from the base of the spikelet rather than the tip), not awns. Yellow Foxtail Grass (S. pumila), a European native, is commonly seen in roadside rights-of-way and disturbed areas in Georgia. It’s 1 - 3 feet tall and the stiffly erect flower clusters are 1 - 6 inches tall, with yellow bristles.


Another grass that looks like Setaria was Purple Bristle Grass or Fountain Grass (Pennisetum sp.). The bristles were purple and much thicker than the yellow foxtail grass. 

Walking down the terraces from the walkway across the field to the road we encountered terraces from the former farm that was located where the Mimsie Lanier Center is now located.  Linda had a chance to talk about the Roosevelt Administration conservation effort in the thirties to get farmers to avoid erosion by making terraces on slopes.  Soon after, farmers reverted back to the old ways plowing straight up hills causing erosion, rather than the contour plowing that saves soil from so much erosion.



At the Mimsie Lanier Center propagation area we saw rows of yellow indian grass:

Yellow Indian grass
Yellow Indian Grass (Sorghastrum. nutans) [occurs] throughout Georgia in dry to moist woodlands and on roadsides. There are long stretches of GA Hwy 15 that are lined with Yellow Indian Grass, which forms large patches by the spread of rhizomes. Both species have upright flower clusters, with the spikelets on branches that encircle the culm, so they look like plumes. The spikelets are golden brown and contrast beautifully with the blue-green leaves and culms. Slender Indian Grass has awns that are 1 - 1½ inches long. Yellow Indian Grass has shorter awns, less than 1 inch.



Indian Grasses have very cool ligules–you can identify them to genus even when they are not in flower. Pull the leaf away from the culm and look for a low membrane with two sharply pointed ears – they always make me think of Yoda. Some people think the ligules look more like rifle sights than they do Yoda.

Georgia Aster
It was great to see the lovely Georgia aster in bloom in a row next to the Indian grass.  It was also cool to see a sample of the silver plume grass at a much earlier stage of growth than it was out on the prairie.  This showed how it gets its name, silver plume grass, because the head had a silvery sheen.


It was time to turn around and head back to the arbor. But along the service road was a trumpet vine with a seed pod hanging on the vine.  We opened it up to see the seeds which were flat with two papery wings. 



It was a good day.  The threatened rain did not materialize until we finished the ramble, and retired to Donderos for refreshment and conversation.



Hugh

SUMMARY OF OBSERVED SPECIES:
Common Name
Scientific Name
Mockernut hickory
Carya tomentosa
Fragrant flat sedge 
Cyperus odoratus
Witch grass
Dichanthelium sp.
River oats
Chasmanthium latifolium
Broomsedge bluestem
Andropogon virginicus
Split-beard bluestem 
 Andropogon ternarius
Purpletop grass
Tridens flavus
Purple lovegrass 
Eragrostis spectabilis
Wild rye
Elymus virginicus
Big top lovegrass
Eragrostis hirsuta
Silver plume grass
Saccharum alopecuroides
Late purple aster
Symphyotrichum patens
Black needlegrass
Piptochaetium avenaceum (Stipa avenacea)
Beaked panicgrass
Panicum anceps
Arrowfeather threeawn
Aristida purpurascens
Tulip tree seeds
Liriodendron tulipifera
Yellow foxtail grass
Setaria lutescens
Purple bristle grass
Pennisetum sp.
Small foxtail grass
Alopecurus sp.
Yellow indian grass
Sorghastrum nutans
Georgia aster
Symphyotrichum georgianum
Trumpet vine
Campsis radicans

3 comments:

  1. Dale, autocorrect got me again. I failed to notice that it butchered the scientific name for big top grass....should be E. hirsuta, not E. hirsute. It always corrects hirsuta to hirsute every time it comes up. Got to see if I can turn autocorrect off!

    Nice report!

    ReplyDelete
  2. Thanks, Don! Correction made. While I was at it I made all the scientific names italicized, as they should have been (and were). When I imported the Word file blogger didn't accept the italics. I hate these softward gotchas.

    ReplyDelete

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