Friday, October 5, 2018

Ramble Report October 4 2018



Today's Ramble was led by Linda Chafin.
Here's the link to Don's Facebook album for today's Ramble. (All the photos in this post are compliments of Don.)
Today's post was written by Linda Chafin (plants) and Dale Hoyt (animals).
Today’s Focus: Warm season grasses in the power line ROW.
27 Ramblers met today.
Announcements:
1.      Alice Woodruff's sculpture and pottery show – “Warrior Women” – is opening Friday evening, October 5, at OCAF, 34 School Street, Watkinsville.
2.      The seat plaque unveiling for seats that the Nature Ramblers purchased will be Tuesday, October 9, at CINE.
3.      Pam announced that Don will have a show of his woodworking at Viva! at the Bottleworks.
4.      The invitation to lunch at Dr. Ali’s home, scheduled for October 11, has to be rescheduled. The new date will be announced in the future.
5.      The Connect to Protect Native Plant Sale is happening Thursday, Friday, Saturday, October 4-6, and October 11-13. Weekdays 4-6 pm, Saturdays 9-11.
6.      Eleven Ramblers met after today’s ramble to organize the NR book group. Our next meeting will be after the October 18, 2018, ramble. At that time each member should bring at least one book recommendation, but not more than three. We will vote on the recommended books to determine which ones we read. For more details please go to our Announcements page.
 Show & Tell:

Richard brought a rambutan fruit to show the group.
Rambutan fruit cut open to reveal what's inside.
Rambutan is a tree in the Soapberry family (Sapindaceae), a plant family found primarily in the tropics (though Georgia does have one species). It’s a close relative of lychee. Richard cut into the coarse husky outer shell to reveal a whitish, round fruit in the center, looking and tasting somewhat like a lychee nut/fruit.


Swamp Sunflowers
Carla brought a nice bouquet of Swamp Sunflowers from her house to show us. Her plants are 14 feet tall! The flowers were gorgeous.



Today's readings:
Linda read the introductory passage from Walt Whitman’s Song of Myself, Section 31:  “I believe a leaf of grass is no less than the journey-work of the stars.
Bob recited a poem he composed in his pre-Nature Ramble days, A Close Encounter with an Old Field.


Today's Route:   We walked down the road to the White Trail, taking the trail toward the power line ROW, first visiting the Prairie Test Plot and then going up the hill in the ROW. We went about half way up before heading back to the Visitor Center and Cafe Botanica, where we enjoyed refreshments and conversation.

Observations:
River Oats

River Oats spikelet

River Oats floret
River Oats is a good grass species to learn on–its reproductive parts are larger than most other grass species. What some folks think looks like a fish dangling from a pole is the basic unit of a grass reproduction, the spikelet. The spikelet is made up of florets, which are small (sometimes microscopically tiny) flowers. The florets have all the necessary parts for reproduction – pistils and stamens – but they are very reduced in size and number. River Oats spikelets contain from 6-17 florets.

Purple Fountain Grass
Purple Fountain Grass is still found around the edges of the powerline right-of-way (ROW), hanging on since the days when this area was a display bed. It is native to open, scrubby habitats in East Africa, tropical Africa, Middle East and SW Asia. It is a widely planted ornamental species with many cultivars that have become invasive.


Bigtop Lovegrass spikelets
Bigtop Lovegrass is at the extreme opposite end of the size continuum from River Oats. Its spikelets are minute (3-4 mm long), with six or fewer florets, and are held at the tips of delicate, spreading branches. The flower cluster (or seed head) is open, airy, and sparsely branched – and up to 2½ feet tall – hence “bigtop.” A close relative we did not see today is the beautiful Purple Lovegrass (Eragrostis spectabilis). While its flower clusters are less than 2 feet tall and a beautiful shade of pink. When the plants fill a long stretch of roadside ditch, they are indeed “spectabilis!”

Crab Grass with stamens and pink, fuzzy stigmas.
Crab Grass is one of three abundant exotic grasses in the ROW, along with Bermuda Grass and Fescue. It’s blooming now and the tiny stamens can be seen dangling from the florets along with the pink, brushy stigmas that comb pollen out of the air.

How do you know if a grassy looking plant is a grass or an imposter? One way to tell is to roll the stem between your fingers. If the stem has 3 sides or edges and is filled with pith, it’s a sedge, a member of the Cyperaceae family. If the stem is round or slightly flattened (with 2 edges) and is hollow, it is likely a grass. Rushes (Juncaceae family) have round stems too, but their stems are filled with pith.

The experimental prairie planting plot has been overrun with a White-and-Yellow sedge, a native that is obviously capable of aggressive growth.

Silver Plume Grass (very tall grasses in the background)

Silver Plume Grass seed heads
Silver Plume Grass is the most conspicuous grass along Georgia’s Piedmont roadsides. Its stems are up to 10 feet tall, erect, and stout. The single seed head is conspicuous at the top of the stem. It starts out in late summer as a silvery pink fan with many spreading branches. After pollination takes place, the fan contracts into a narrow spike-like shape as the seeds mature. Once the seeds are ripe and ready to disperse, the seed head opens in a large, hairy plume (up to 12 inches long and 4 inches wide) waiting for the wind to come along and blow the seeds in every direction. Each spikelet is equipped with long, silky hairs and stiff, twisted bristles that aid in dispersal.

Vasey Grass, also know as Dallis Grass, is one of many exotic invasive grasses in Georgia; this one is native to South America. It has many short branches at the top of its stems, each bearing stacks of round spikelets.

Purple-top seed head
Purple-top or Greasy Grass is past its prime, having flowered several weeks ago. The delicate arching branches are still obvious though, and some of the seed heads still have the wax-coated spikelets that give them that greasy feel. Most of the plants we examined are infected with Black Smut Fungus.

Splitbeard Bluestem; note the V-shaped seed head

Splitbeard Bluestem showing the red and green colored bands on the stem.
Splitbeard Bluestem is just coming into flower now, and the characteristic pair of V-shaped spikelets has not fully developed. With a little teasing, we were able to separate the young seed heads into a pair. More obvious, and also diagnostic for this species, are the bands of color that encircle the stems. The leaf sheaths are blue-green and the exposed stretches of stem between sheaths are reddish, so “red stem” would be a more accurate name than bluestem (but Ramblers are more than inured to the vagaries of common names by now). We compared the stems to those of its near relative, Broomsedge, which lacks the colored bands–its stems are solid green color. Broomsedge is weeks away from flowering, but we’ll be back for it.

Beaked Panicgrass; each spikelet has a short beak
Beaked Panicgrass has a large seed head made up of two-flowered spikelets carried at the tips of spreading branches. Each spikelet has a short beak.

Velvet Witchgrass
Velvet Witchgrass is one of the few Witch Grasses that are easily recognized in the field: its leaves, stems, and leaf sheaths are covered with soft, short hairs.

Late Purple Aster
Late Purple Aster is in flower, with its beautiful purple ray flowers and yellow disk flowers that will turn red with age.

Praying Mantis on Silver Plume Grass seedhead

Praying Mantis on camera for size comparison
Praying Mantis. Autumn is the time of year when we begin to notice Praying Mantises, not because they make their first appearance then, but because they are so small earlier in the year. In the fall the female mantis lays an egg case that contains approximately 50 +/- eggs. In the following spring the eggs hatch and all the tiny mantises disperse and begin eating other insects, slowly growing through five molts to reach the size of the mantis we saw today.
A mantis is a “sit and wait” predator. It selects a spot that is frequented by potential prey, like a grass seed head or a cluster of flowers. Then it waits for an insect to visit. When its prey is within striking distance the mantis captures it with its raptorial fore legs. (Called raptorial because they serve the same function as a raptor’s clawed feet.)
A praying mantis is often recommended as a pest control solution for the garden. But mantises are not selective, eating whatever they can catch. In other words, they don’t discriminate between harmful and beneficial garden insects.

Banded Garden Spider on its web
Compare with the Golden Garden spider, below.
(Note bands on legs, appearence of stabilimentum)


Golden Garden Spider on its web
Compare with the Banded Garden spider, above.
(Note bands on legs, appearence of stabilimentum)
Banded Garden Spider. Today’s surprise find was what we first thought was a Golden Garden Spider on its web among the grasses. But a more careful look revealed that it was a related species – the Banded Garden Spider. This is the first time we’ve seen this species on a Ramble.
Banded Garden Spider with captured grasshopper at lower left

Captured grasshopper showing the silk wrapping
Just after we had finished looking at the spider a grasshopper blundered into its web. The spider rushed over and enswathed the grasshopper with wide bands of silk. Many orbweavers wrap their prey up in silk and then bite it after it is securely bundled up. The bite injects a venom that typically paralyzes the prey. When prey are abundant a spider can collect several and eat them when they are less busy.
Spiders have several kinds of silk glands; orb weavers as many as six types. Each type of gland produces a silk with different properties. The glands open into spinnerets from which the liquid silk is pulled by the spider’s feet. It rapidly polymerizes as it is pulled out. Different silks are produced for different tasks: draglines, web frames, wrapping silk, stabilimentum silk, sticky spiral silk and silk for constructing egg sacs. glue glands. Silk has very high tensile strength and performs better than Kevlar, the material used in body armor. This has been known since the work of a Dr. Goodfellow, of Tombstone, Arizona. (Dr. Goodfellow was the physician in Tombstone at the time of the Gunfight at the OK Corral.) He reported several instances in which a bullet failed to penetrate silk handkerchiefs.
“The third patient was shot through the neck at close range from a Colt 45-caliber revolver. Dr. Goodfellow attributed the patient’s survival to the loosely tied silk handkerchief around his neck. The entrance wound was so severe it had exposed his right carotid artery, and any liquids he drank flowed out of the wound for several weeks into his recovery. However, once again the silk was drawn into the wound but was uncut by the bullet.” (Lee, J.K. (2016). Bulletproof Silk: Observations of Dr George E. Goodfellow, the Gunfighter’s Surgeon. J Am Osteopath Assoc 116, e97–e98.) 
Spider silk should perform even better.

SUMMARY OF OBSERVED SPECIES:

River Oats
Chasmanthium latifolium
Purple Fountain Grass
Pennisetum setaceum
Bigtop Lovegrass
Eragrostis hirsuta
Crab Grass
Digitaria sp.
Perilla Mint
Perilla frutescens
Sedge
Carex sp.
Silver Plume Grass
Erianthus alopecuroides
(= Saccharum alopecuroides)
Praying Mantis
Mantodea: Mantidae
Vasey Grass
Paspalum urvillei
Purpletop Grass/Grease Grass
Tridens flavus
Splitbeard Bluestem
Adropogon ternarius
Banded Garden Spider
Argiope trifasciatus
Beaked Panicgrass
Panicum anceps
Velvet Witchgrass
Dichanthelium scoparium
Late Purple Aster
Symphyotrichum patens
Yellow Star Grass
Hypoxis hirsuta