Ramble Report June 17 2021

Today's leader: Linda Chafin
Today's Route: Alice H. Richard's Children's Garden, the Lower Shade Garden and the Dunson Native Flora Garden.
Number of Ramblers:  22

Reading:  Inspired by the coming summer solstice, Linda read a passage from North With the Spring, by Edwin Way Teale

Everywhere in the Northern Hemisphere Spring had come and gone. The season had swept far to the north; it had climbed mountains; it had passed into the sky. Like the wind, Spring moves across the map invisible. We see it only in its effects. … It appears like the tracks of the breeze on a field of wheat, like shadows of wind-blown clouds, like tossing branches that reveal … the passing of the unseen. So Spring had spread from Georgia to North Carolina, from Virginia to Canada, leaving consequences beyond number in its wake. We longed for a thousand Springs on the road instead of just this one. For Spring is like life. You never grasp it entire; you touch it here, there. You know it only in parts and fragments. Reflecting thus on the first morning of Summer … the Summer solstice, the longest of the year, we were well aware that it is only on the calendar that Spring come to so sudden a termination. In reality its end is a gradual change. Season merges with season in a slow transition into another life.

 Announcements:

       Carla offered seeds from her hibiscus to those that wanted some

.
       Linda introduced the idea of a Garden Butterfly Trail to the group.  She and Sandy have been working on presenting the idea of the Garden Butterfly Trail to Jenny-Cruze Sanders, Director of the Garden.  It would be affiliated with the Rosalynn Carter Butterfly Trail program, a state-wide effort to promote butterflies as beautiful and beneficial insects in our environment, emphasizing and promoting the importance of providing plants for various species of butterflies.  Existing plants will be inventoried to see which plants may need to be increased in numbers, as well as which new plants might be needed to be added to provide not only plants for pollination and nectaring, but also as host species for egg laying and caterpillar food.  The importance of eliminating competing invasive plants to provide more habitat for pollination and hosting will also be a part of the proposal.

By voice vote the Ramblers present approved the initiative.
 

 Nature Ramblers started the morning by visiting the Children's Garden and admiring the many native wetland and aquatic species planted there.

Horsetails

 

Horse-tails are a group of ancient plants - "living fossils" - that appeared prior to the Devonian era, 350+ million years ago.

Horsetail strobilus

They reproduce by spores, not seeds, that are produced in cone-like structures (strobili)  at the tips of the stems. Horse-tails are found nearly world-wide, but in Georgia, we have just one species which occurs only in a few Coastal Plain counties. 

Horsetail ("Scouring Rush") stem.
White flecks are silicate crystals.

Sometimes called "scouring rush," Horsetail stems are coated with abrasive silicates that make them good for scrubbing pots.

White Water Lily'

Obedient Plant

Obedient Plant has all the earmarks of a member of the Mint Family: its stem is more or less square in cross-section, the leaves are opposite, and the flowers are two-lipped. The name refers to the fact that the flowers can be pushed into odd positions where they remain "obediently." Okay, yes, it is a stretch.

Lizard Tail

Lizard Tail is another primitive plant, one of the oldest flowering and seed-producing plants, having been around for about 20 million years. Its long, showy flower spikes with curving tips inspired both the common name and the genus name (Saururus, derived from Greek sauros, meaning lizard.) The flowers have neither petals or sepals, and are primarily wind pollinated, but the glowing white stamens, pistils, and flower stalk combine to attract some insects. Lizard Tail occurs abundantly at the Garden in the Middle Oconee River floodplain and throughout the eastern U.S.

Button Bush

Button-bush is a beautiful wetland shrub with spherical flower heads composed of many tiny white flowers whose stamens radiate outward like the protein spikes on the coronavirus. The flower heads are pollinator magnets, attracting a wide array of insects, especially bees. Its leaves are hosts for the larvae of several large moth species.

Sacred Lotus

Sacred Lotus, Nelumbo nucifera, is native to a broad swath of Asia. A close relative, Yellow Lotus  (Nelumbo lutea), is found in wetlands throughout much of the eastern U.S.

Water Primrose

Pitcher plants

The Dunson Garden is a very different place now than it was only two months ago, when the trees were bare of leaves, sunlight lit up the forest floor, and many colorful wildflowers were in full bloom. Now, in late spring and early summer, the forest is largely a sea of green. Less than 5% of the sun's energy actual reaches the forest floor now. We saw many species in fruit or beginning to disperse their seeds.

Dwarf Pawpaw fruits

White Avens fruits

Black Cohosh

However, one native species - Black Cohosh - is lighting up the Dunson Garden now with its tall white candles. The flower clusters are racemes (hence the species name, racemosa). These are spike-like arrangements of flowers held on tiny stalks. Each flower consists of a starburst of about 24 white stamens surrounding a single white pistil - there are no petals and its five tiny white sepals fall off early. Flowers in the raceme open from the bottom up, with flowers at the bottom of the spike beginning to produce fruits even while flowers at the top are still in bud. In spite of - or maybe because of - their unpleasant odor, Black Cohosh flowers are insect magnets. A variety of bees, flies, and beetles can be seen flying and crawling over and between the flowers, collecting pollen for their own consumption and to take back to their larval young (there is no nectar). Only about 2% of the pollen they collect is actually brushed onto another flower. Given the fondness of insects for Black Cohosh, it is a mystery why the species is also called Bugbane (bane = trouble or poison). But the genus name Cimicifuga (only recently changed to Actaea) may explain it. Cimi means bug and fuga means to drive away - suggesting that the plant may have been used to expel insects from homes, a practice called "strewing" where certain dried plants are spread across the floor as bug repellents and air cleansers.
The underground stems (rhizomes) of Black Cohosh are black and, when dried and powdered, have been used to treat side effects of various "female ailments" such menopause, PMS, and osteoporosis. Results of research on the efficacy of these products are inconsistent.

Sanicle or Canada Black Snakeroot

Canada Black Snakeroot. Less showy than Black Cohosh - much less showy, in fact, downright inconspicuous - are the flower clusters of Sanicle or Canada Black Snakeroot which is abundant in the Dunson Garden this year. Its flowers are tiny, white, and 4-petaled and held in small clusters at the tips of short stalks. If there is a conspicuous feature of this plant it is the fruits, which are covered with hooked bristles that readily attach to feathers, fur, and socks for seed dispersal. The leaves of Canada Black Snakeroot consist of 3 leaflets; the lower two leaflets are often subdivided so that the leaves sometimes look 5-parted. Truly five-parted leaves are found on the also common Sanicula marilandica (Maryland Black Snakeroot).

 

May-apple is now bearing fruits that will be eaten by a number of animals, notably box turtles. Its leaves are showing signs of senescence and will be gone within a few weeks with the help of a fungus. 

Mayapple Rust
Alan Rockefeller, Wikimedia Creative Commons

Mayapple Rust (Allodus podophylli), a fungal disease, attacks the leaves of May-apples in late spring, creating yellow blotches on the upper surface of the leaves and patches of orange pustules (turning to brown) on the lower surface. While fatal to seedlings, the rust seems to infect mostly aging leaves and does not kill the plant. Most rust diseases require an alternate host, like the famous cedar-apple rust, which lives half its life cycle on apple trees and the rest on Eastern Red Cedars, but Mayapple Rust is found only on a single host.

Goldenseal with its raspberry-fruits

Four-winged Silverbell

Four-winged Silverbell fruits have four conspicuous wings. Another Silverbell species, Two-winged Silverbell, occurs primarily in the Coastal Plain.

Fly-poison

Fly-poison flowers start out pure white and turn green with age. All parts of the plant are toxic to mammals, especially the bulb, but the flowers are insect-pollinated.

Golden Ragwort leaf mines

Golden Ragwort leaf miner. As hard as it is to believe, there are insects - called leaf miners - that live in the vanishingly small space between the upper and lower epidermal layers of a leaf, feeding on soft, green tissue called parenchyma. Leaf miners are usually the larvae of either flies or moths. The adult lays an egg on the leaf, which hatches to produce the larva. The larva burrows into the leaf and begins to eat its way through the leaf tissue leaving a trail of surface cells that are devoid of chlorophyll. The trail will be white if the larva doesn't defecate or brown if it does. 

This remarkable photo by Don Hunter captures a caterpillar emerging from its leaf mine.
The caterpillar is the small, white object in the center of the photo.

In Dunson, Golden Ragwort leaf miners - the larvae of a moth - are common. They lack an anus and therefore leave a clean, white trail. As the larva feeds and grows larger, winding its way in curving loops within the leaf tissue, the width of the trail increases until finally the larva emerges and falls to the ground to pupate in the leaf litter.

Golden Ragwort Leaf Miner moth, Phyllocnistis insignis
 Andy Reago and Chrissy McClarren, Wikipedia Creative Commons

 

An adult Green Lacewing fly
(Alvesgaspar [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)])

 

 

 

Green Lacewing larvae and adults are both predators of aphids and other plant-sucking insects called plant hoppers.

The larval stage of the Green Lacewing are aptly  name of "aphid lions." Their primary prey are the sap-sucking insect larvae of plant hoppers and aphids. Aphids and plant hoppers feed on sugar-containing sap and they are often protected by ants. In return, the sap-suckers give the ants a share of their sugary meal by excreting a drop of sweet fluid. The ants recognize the sap suckers by their odor. (Ants have poor vision but exquisite olfactory abilities.) The Lacewing larva takes advantage of the ant's reliance on odor and turns it into a weakness. When a Lacewing larva finishes sucking the body fluids from its prey it places the empty corpse on its back. As the dead bodies accumulate more and more of the larva is covered with the odor of its victims. The ants are fooled into thinking that the Lacewings are just another sap sucker.Other kinds of plant sucking insects called plant hoppers are also preyed upon by lacewings. Some of these insects secrete waxy threads that cover their body, protecting them from parasitic insects. But these defenses don't stop the lacewing larvae. They simply include the waxy material with their morbid decorations.

 

...A lacewing larva hidden beneath the waxy corpses of its planthopper prey.

The lacewing larva from the photo above,turned over to reveal the larva beneath the wax. The hollow, hooked jaws are at the top.

Planthoppers feeding on a plant. The white fluff is wax that covers the body of the insect.

Bottlebrush Buckeye

Bottlebrush Buckeye is in flower along the Garden's entrance road and in the formal garden, just beyond the Flower Bridge, producing large, showy clusters of white flowers. It is a large, sprawling shrub in the same genus, Aesculus, as the early spring-flowering Painted Buckeye and Red Buckeye. The following was extracted from two essays about Bottlebrush Buckeye flowers written for this blog by Dale Hoyt on June 23, 2016 and June 18 2015:
"The Bottlebrush Buckeye has numerous panicles containing up to a hundred or more flowers each. Each flower has 4-6 stamens that project far beyond the petals. The stamens are literally crawling with small bees stuffing the pollen from the anthers into their pollen baskets. This leads to a question: are these tiny bees pollinating the flowers or are they just stealing pollen? To be a pollinator an insect not only needs to pick up pollen, but it needs to carry that pollen to the female part of a flower, the pistil. More specifically, it needs to deposit the pollen on the stigma of the pistil. The insect doesn't need to be aware that it is doing this, it just needs to brush against the stigma to deposit some of the pollen adhering to its body. So the question we asked ourselves was: are these bees likely to blunder into the stigma? But when Hugh [Nourse] and I
looked for pistils in the flowers we couldn't find any! Something interesting was going on here and it would take a little research to find out what it was. It turns out that the Bottlebrush buckeye is what botanists call andromonoecious, a fancy word that means that each plant carries a mixture of flowers that are complete and flowers that have only stamens. (A complete flower has both stamens and pistil, i.e., both male and female parts.) Furthermore, this plant has, on average, only around 4-5% complete flowers, so out of every thousand flowers only about 50 are capable of producing seed. Can the tiny bees do the job? It seems unlikely that they would be effective pollinators since they spend most of their time hanging onto the anthers. But a recent study suggests a different, more likely pollinator. The Flame azalea has a flower that is similar to the Bottlebrush buckeye in that it's stamen stick out way beyond the petals and the pistil does the same. The principal pollinator of the Flame azalea is the Tiger Swallowtail butterfly. It transfers pollen from stamens to the pistil with its wings!! Here's how: when swallowtails get nectar from flowers they hover in front of the flower with their wings flapping. The flapping wings touch the anthers and get showered with pollen. They also come in contact with the stigma of the flower and subsequent flowers that the butterfly visits. So the pollen that adheres to the wings inadvertently gets transferred to the female structures of the next flower the butterfly visits. If it works this way for the Flame azalea it might work the same way for the Bottlebrush buckeye. We'll have to watch for swallowtails on our future rambles." [Dale Hoyt, June 18, 2015]
"If you look carefully at each raceme with its hundreds of flowers you may notice that most of them have only stamens. Only a small percentage of the flowers are perfect (that is, contain stamens and pistils, the male and female parts). The perfect flowers are difficult to find because the style of the pistil is long, thin and the same color as the filaments of the stamens. It lacks the small brown anther at the end, but some older stamens have lost their anthers also. 

Bottlebrush Buckeye fruits are produced at the top of the inflorescence

There is a Bottlebrush buckeye on the sidewalk just beyond the Flower bridge and has dropped most of its petals. The perfect flowers on that plant stand out as their swollen ovary at the base of the pistil still bears the style. If you're interested, you can count the number of perfect flowers and the total number of flowers on a raceme. It should come out to about 4% perfect. This condition of bearing some perfect and some male flowers is called andromonoecious. The andro- prefix means male and the -monoecious suffix means one house - both sexes on the same plant." [Dale Hoyt, June 23, 2016]

SUMMARY OF OBSERVED SPECIES:

White Wild Indigo	Baptisia alba
Butterfly Bush	Buddleja davidii
Seychelles Pole Bean	Phaseolus vulgaris
Obedient Plant	Physostegia virginiana
Lizard’s Tail	Saururus cernuus
Water Primrose	Ludwigia hexapetala
Papyrus Sedge	Cyperus papyrus
Horsetail	Equisetum hyemale
American White Water-lily	Nymphaea odorata
Button Bush	Cephalanthus occidentalis
Sacred Lotus	Nelumbo nucifera
Various pitcher plants	Sarracenia sp.
St. Johns Wort	Hypericum frondosum
Bumblebee	Bombus sp.
Western Honeybee	Apis mellifera
Pomegranate	Punica granatum
Pawpaw	Asimina triloba
American Pokeweed	Phytolacca americana
Bottlebrush Buckeye	Aesculus parviflora
Canada Black Snakeroot	Sanicula canadensis
Black Cohosh	Actaea racemosa
Goldenseal	Hydrastis canadensis
Mayapple	Podophyllum Peltatum
Mayapple Rust	Allodus or Puccinia podophylli
Fly Poison	Amianthium muscitoxicum
Common or Mountain Silverbell	Halesia tetraptera
Painted Buckeye	Aesculus sylvatica
White Avens	Geum canadense
Golden Ragwort	Packera aurea
Dwarf Pawpaw	Asimina parviflora
Big-leaf Magnolia	Magnolia macrophylla
Green Lacewing (larva)	Chrysoperla rufilabris
Rice-paper Plant	Tetrapanax papyrifer
Planthopper	Hemiptera: Flatidae