Today's Ramble was led by Linda Chafin.
The photos in this post, except where
noted, came from Don Hunter's Facebook album (here's the link).
Today's post was written by Linda
Chafin.
27 Ramblers met today.
Today's reading: Bob Ambrose
recited (from memory) Robert Frost's Nothing
Gold Can Stay:
Nature's
first green is gold,
Her hardest hue to hold.
Her early leaf's a flower;
But only so an hour.
Then leaf subsides to leaf,
So Eden sank to grief,
So dawn goes down to day
Nothing gold can stay.
Today's Route: We left the entrance plaza at the Visitor
Center and headed down the paved path, past the American South bed and across
the Flower Bridge. We passed through the
China and Asia Section, the Rare and Endangered bed and across the Native American
and Southeastern Tribes section, skirting the Herb and Physic Gardens before
arriving at the Heritage Garden. We then
made our way down into the Flower Garden, concentrating on the cherries, crab
apples and blueberries before heading back to the Visitor Center.
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Cedar Waxwings basking in the sun. |
As we gathered at the Visitor Center Fountain Plaza, we
noticed a lot of activity in the Palatka Holly trees around the plaza. Many
Cedar Waxwings were basking in the sun striking the upper branches, while
others were foraging on the holly berries.
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Japanese Maple leaf and flower |
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The Japanese Maples along the
Visitor Center sidewalk have partially leafed out and begun to bloom. Maples,
both native and exotic, are among the first trees at the Garden to flower. Our
native Red Maples flowered in February and have gone to seed. Maples are
monoecious, meaning that male flowers (with stamens) and female flowers (with
pistils) are found on the same tree. Some maples are functionally dioecious, that is, they act or function as though the male flowers and female flowers are on
separate trees. In maples, the male flowers on some trees don’t actually
produce pollen, so that only the female flowers are actually functioning. We looked at several female flowers on the
Japanese Maples, their styles protruding out from the small, red flowers, and saw
no stamen-bearing flowers, so perhaps this tree was functionally female. Maples are generally thought to be
wind-pollinated: their flowers are inconspicuous and open in late winter before
most insects are active. But bees do visit maple trees, especially Red Maples
and Sugar Maples, to gather nectar so at least some of the pollination is
carried out by insects. There is a nice article on Japanese maples at this
website: https://naturewalk.yale.edu/trees/aceraceae/acer-palmatum/japanese-maple-42
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Redbud showing cauliflory |
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Redbud flowers |
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Several Eastern Redbuds are
in flower along the path into the International Garden. We stopped to admire
the strange phenomenon of cauliflory, where flowers emerge directly from the
bark of the branches and trunks of the trees. Some of the Redbud trees planted
in the Garden may have been horticulturally selected to maximize cauliflory,
but it also occurs frequently in wild trees as well. Cauliflory is mostly found
in tropical shrubs and understory trees; Redbud is one of the few temperate
species to exhibit this trait. Curious minds want to know: how and why? Studies
done in just the last couple of decades have answered these questions. There
are two parts to the “how” answer. Redbuds produce in each leaf axil up to ten
“first order” flower buds that can remain dormant for up to five years and that
flower sequentially on small branches during those five years. But what about
the flowers on older, larger branches and even on the trunks? It turns out that
first order buds have the ability to produce “second order” buds that go on
flowering indefinitely on ever enlarging branches and trunks. And what about
the “why” question, so dear to Ramblers, and often so hard to answer? Botanists
know that the closest relatives to Eastern Redbud are tropical cauliflorous
species, so this ancestral trait was apparently carried along as Redbuds
evolved to live in temperate areas. But why cauliflory in the first place? What
advantage does cauliflory confer on some tropical plants? Most tropical species
with this trait are understory trees, attracting a different set of pollinators
than the flowers in the upper reaches of the canopy. So perhaps cauliflory
evolved to attract and provide nectar for the low-flying insects, such as heavy-bodied
bees, that never make it up into the
canopy. For a more detailed discussion of cauliflory, this is a good
article: “Redbud
Cauliflory: The Inside Story,” by John Hayden. https://scholarship.richmond.edu/biology-faculty-publications/127/
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Chattahoochee Trillium with "youngsters" | |
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Virginia Bluebells |
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Woodland Phlox |
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Several native wildflowers
are flowering along the path into the International Garden, including Virginia
Bluebells, Woodland Phlox, and a small “family” of Chattahoochee Trillium, with
a large, flowering plant and various two- and three-leaved “youngsters” around
its base that will mature and bloom over the next few years.
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Georgia Rockcress |
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Gerogia Rockcress closeup |
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There are several beds of Georgia
Rockcress in full bloom in the International Garden. This is one of the most
endangered species in Georgia, with only a handful of populations surviving in the
northwest corner of the state near Rome and in the Fall Line, near
Columbus. They love rocky cliffs and
bluffs, or perhaps they inhabit these stressful environments because there’s
little competition. They are clearly flourishing in the rich beds at the
Garden. Georgia Rockcress is one of the top priority species of the Georgia
Plant Conservation Alliance and has also been nominated for federal listing as
legally Endangered.
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Pansy | |
The Flower Bridge is adorned with planters
filled with large-flowered pansies, which some Ramblers were surprised to learn
are actually cultivars of wild violets (in the genus Viola). The many shapes and colors of pansies are the result of
artificial (human-induced) hybridization among several species in the section
of the Viola genus called Melanium. Wikipedia tells us that the
name pansy “is derived from the French word pensée
(thought), and was imported into Late Middle English as a name of Viola in the
mid-15th century, as the flower was regarded as a symbol of remembrance.”
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The flowering stalk of Grass-leaf Sweet Flag |
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Planted among the pansies is a strange
little plant with grass-like leaves and an erect spike of yellow-green
flowers. It turns out to be Grass-leaf Sweet Flag, Acorus gramineus cultivar Ogon. Neither a sedge nor a grass, it's in the Sweet-flag or Calamus family, sister to all the other monocotyledonous plants. It is not native to US; native to Japan, Korea, and Eastern Asia.
The yellow-green spike (spadix) consists of tightly packed little
ovaries that will become small red berries, if they are fertilized. Tucked in among the female flowers are tiny male flowers that will present their stamens later to prevent self-pollination.
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Cupflower | |
At the back edge of the International
Garden, there is a pretty little groundcover flourishing between the pavers.
Known as Cupflower, it’s a white cultivar ‘Alba’ of a creeping species of Mazus.
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Alabama Snow Wreath |
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The large hedge of Alabama
Snow Wreath at the entrance to the Threatened and Endangered beds is in peak
bloom. This is a beautiful shrub, with long, arching boughs covered with showy white
flowers. The flowers have no petals, just a cluster of long, white stamens. Found
in Georgia only in two northwestern counties, it occurs naturally in rocky,
limestone-based forest soils. It spreads largely by underground stems; seeds
are seldom seen. The genus Neviusia
has only two species in it, ours (Neviusia
alabamensis) and one other in California. It is in the Rose Family.
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Pawpaw flowers |
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The Pawpaw trees
near
the entrance to the Heritage Garden are covered with many buds and barely open
flowers. Dark maroon in color, the flowers are thought to attract pollinating
flies and beetles by a hue that suggests rotting meat. But however pollination
occurs, it doesn’t seem to result in much fruit formation here at the Garden or
elsewhere. In their article “Pollinator
limitation, fruit production, and floral display in pawpaw (Asimina triloba),”
Mary Willson and Douglas Schemske state that less than one percent of flowers
produce fruit. Looking closely at the open flowers, Ramblers could easily see a
well developed green ovary but no stamens, the “female” part of a given flower
developing well before the “male” stamens, thereby preventing self-pollination.
Perhaps this system works too well? Since Tall Pawpaws grow in large clonal colonies,
pollen transferred from their closest neighbors, which are genetically the same
plant, won’t result in fertilization. Flies and beetles have to travel long
distances between pawpaw patches to effect cross-pollination and
cross-fertilization. It is apparently established practice among commercial
pawpaw growers to hang a dead animal in their pawpaw patches to encourage
pollinators to move around among plants and patches!
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Flowers of 'Belle of Georgia' peach |
Several large ‘Belle of
Georgia’ peach trees were blooming near the edge of the Heritage Garden.
Peaches are in the same genus, Prunus,
as cherry trees, which are also flowering now. Both have the characteristic bark
trait of conspicuous horizontal rows of lenticels, the spongy tissue that
allows the plant to uptake carbon dioxide through its bark.
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Crabapple cultivar 'Louisa' |
One of the Crabapple cultivars, 'Louisa,’
is flowering beautifully now at the edge of the Flower Garden, its sign prompting
a discussion of the meaning of “cultivar” and how it differs from the term “variety.”
The word “cultivar” is a portmanteau (a word that combines the meanings of two
other words, like brunch); cultivar is simply shorthand for “cultivated
variety.” A type of plant that has been developed horticulturally by
hybridization or other artificial breeding techniques is called a cultivar and
given a non-Latin name that is shown in single quotation marks, hence ‘Louisa.’
Usually the cultivar name is preceded by
the Latin name: Malus angustifolius
‘Louisa.’
On the other hand, the term “variety” is applied
by botanists to a group of plants that differs consistently, perhaps with a
different leaf or flower shape, from other plants in that species in ways that
suggest that the group is on the way to evolving into a new species. So:
variety is used for the result of a natural process and cultivar is used for
the result of an artificial process.
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Henbit | |
Several weedy European
wildflowers are flowering now in the edges of flower beds and in sidewalk
cracks. These are among the first wildflowers that many of us learned – they
are conspicuous and easy to identify, and, though exotic, are not invasive or
found in natural areas. Henbit and Dead-nettle are both in the mint family, as
their square stems, opposite leaves, and two-lipped flowers testify. Hairy
Bittercress has leaves with up to nine rounded leaflets and the sharp odor of
plants in the Mustard Family.
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Two lichens |
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Some of the brick walls in
the Heritage Garden are covered with patches of gold- and gray-colored lichens,
whose identity await the arrival of lichen experts!
SUMMARY OF
OBSERVED SPECIES:
Cedar Waxwings
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Bombycilla cedrorum
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Palatka Holly; hybrid of
two native hollies
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Ilex cassine
x Ilex opaca
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Japanese Maple
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Acer palmatum
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Eastern Redbud
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Cercis canadensis
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Chattahoochee Trillium
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Trillium decipiens
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Virginia Bluebells
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Mertensia virginica
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Woodland Phlox
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Phlox divaricata
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Georgia Rockcress
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Arabis georgiana
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Pansy
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Viola section Melanium
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Cupflower
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Mazus reptans 'Alba'
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Alabama Snow Wreath
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Neviusia alabamensis
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Primrose-leaved Violet
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Viola primulifolia
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Dwarf Sumac
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Rhus michauxii
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Paw Paw
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Asimina triloba
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Creeping Fig
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Ficus pumila
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Belle of Georgia Peach
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Prunus persica
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Flowering Crabapple
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Malus angustifolius 'Louisa'
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Rabbiteye Blueberry
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Vaccinium ashei
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Henbit
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Lamium amplexicaule
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Hairy Bittercress
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Cardamine hirsuta
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Several species of lichen
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