Today's Ramble was led by Linda Chafin.
The photos in this post, except where noted, came from
Don's Facebook album (here's the link).
Today's post was written by Dale Hoyt.
34 Ramblers met today.
Announcements:
Art opening at the Georgia
Museum of Art, May 18th.
Works of art owned by Deen Day Sanders.
Friends of the Garden get in free.
RSVP.
Today's reading:
Bob Ambrose recited his latest poem, The Business of High Spring, a
counterpoint to last week's poem.
Bob also says: "I'll be giving a lesson
"Genesis 1 - A Modern Telling" the next two Sundays (May 6 and 13).
It will be in the Cornerstone Sunday School class in the First United Methodist
Church (downtown), 9:50 - 10:50 a.m. If
any rambler is interested in coming by, I could give them directions to the
class."
You
can contact Bob here: bobambrosejr AT gmail.com
Today's route: Down the cement walkway through the Shade
Garden and then through the Dunson Native Flora Garden.
Visitor's Center:
A large Chinese Fringe Tree is blooming at the front of
the Visitor Center. Although this specimen is not native to North America, we
do have a native species that is similarly spectacular when it blooms (Chionanthus virginicus), known by
several common names: Fringe Tree, Old-Man's Beard or Grancy Gray-beard.
Upper Shade Garden
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| Ohio Spiderwort Do those hairs look like a spider to you? |
Spiderworts are in bloom all over the garden. The first
one we encountered is the Ohio Spiderwort. The spiderwort name is supposed to
be based on the similarity of the fuzzy stamens to a spider. Only a botanist
could think this looks anything like a spider.
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| Sparkleberry in bloom |
Also beginning to bloom is Sparkleberry, a shrub or small tree in
the Blueberry genus, Vaccinium. The
fruits ripen in the fall and are eaten by wildlife, but have a
disagreeable taste to humans. The common name is based on the glossy leaves
that shine attractively in sunlight.
On our way down the sidewalk the Red-shouldered Hawk flew overhead, carrying a branch
in its mouth to its nest in the Sycamore. We saw the female on the nest last
week.
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| Mariana Maiden Fern |
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| A single frond of the Mariana Maiden Fern demonstrating the bipinnate structure. |
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| Christmas Fern with pinnate fronds |
Looking at the photo of the Christmas fern, above, you'll notice a large number of small green leaflets attached in pairs to a central stalk. Three such stalks with attached leaflets are clearly visible. The stalk is called a rachis; the part of the rachis to which the leaflets are attached is called the stipe. And, yes, there is a special name for the leaflets: pinna (singular) or pinnae (plural). The entire leafy structure is called a frond. You'll also notice that the pinnae of the Christmas fern are arranged pairwise along the stipe, similar to the way a bird's feathers are constructed. This is called pinnate.
Look at the Marianas Maiden Fern in the photo above the Christmas Fern. It shows another level of complexity. Linda is holding one enormous frond. It is pinnately subdivided and each subdivision is, itself, pinnately divided into numerous pinnae. Where the Christmas fern is pinnate, the Marianas Maiden Fern is bipinnate. Look closely at the smallest pinnae. They are only partially subdivided. The lobes are not entirely separate and they are connected by a ridge of green, leafy tissue to adjacent lobes. This incomplete separation of the pinnae is call pinnatifid. So the proper discription of the Marianas Maiden Fern is: bipinnate pinnatifid.
If the pinnae were completely separate the fern would be described as tripinnate.
As Kathy pointed out, this repetition of structure can be described as fractal: the same structure is visible at different scales; i.e., the structure is self-similar.
Test your knowledge of fern structure. Here is a photo of a Broad Beech Fern. Is it pinnate, bipinnate, tripinnate or something else?
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| Broad Beech Fern How would you describe its structure? |
Fern reproduction is by spores that are produced in structures called sporangia. The sporangia are gathered together in clusters called sori (plural) or a sorus (singular). The sori are found in different locations, depending on the kind of fern. In many species the underside of the pinae is where they develop. In some species every frond bears sori; in others only some of the fronds have sori and in some ferns a separate, highly modified frond bears nothing but sporangia. Each of the following three photos shows different arrangements of the sori in Marsh Fern, Christmas Fern and Rattlesnake Fern.
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| Sori on the undersurface of Marsh Fern pinnae |
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| Sori on the undersurface of Christmas fern terminal pinnae. |
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| Fertile frond of Rattlesnake Fern |
Ricepaper plant@Styrax?
Bigleaf Magnolia@Magnolia macrophylla
Pale Yellow Trillium@Trillium
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| Oakleaf Hydrangea |
Oakleaf Hydrangea. The derivation of the genus name, Hydrangea, does have something to do with water. It comes from the Latinization of the Greek hudro- ‘water’ + angeion ‘vessel,' and refers to the cup shape
of its seed capsule.
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| A fan of Dwarf Crested Iris leaves with the clover-like leaves of Violet Wood Sorrel in the lower right. |
Iris leaves are arranged in overlapping fan of flat leaves
Grasses can be divided into two groups: Cold season or Warm season. Cold season grasses overwinter and begin to flower in spring. Warm season grasses begin growth in the spring and flower when they mature in the fall.
A we noted last week the above ground parts (leaves, fruits) of true Ephemeral spring flowers, e.g.,
Trout Lily, have completely disappeared. The leaves of other early spring flowers will persist for much longer (Bloodroot), even overwintering (Hepatica).
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| Jack-in=the-Pulpit; the spadix is just visible peeking out of the spathe (the "pulpit"). |
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| A group of Jack-in-the-Pulpits |
Partridge berry is a small, ground hugging plant that has white flowers growing in pairs. Their ovaries become fused, producing a single fruit.
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| Fringed Campion flowers |
Fringed Campion was the surprise of the day.
Mayapple leaves have yellow spots from a fungus infection called mayapple rust. Many rust fungi alternate between two different hosts, but mayapple rust just sticks to one species. On the underside of each yellow spotted leaf you'll find the spore releasing structure of the fungus.
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| Flowers of Oriental False Hawksbeard |
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| Basal leaves of Oriental False Hawksbeard |
Oriental False Hawksbeard seems to found everywhere in the Garden at present. I asked Don to photograph the small yellow composite flower heads that look like tiny dandelions as well as the basal leaves, also dandelion-like, so that you will become aware of this plant and pull it from your yard if you find it growing there.
SUMMARY OF OBSERVED SPECIES:
Visitor's Center
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Chinese Fringe Tree
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Chionanthus
retusus
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Upper Shade Garden
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Ohio Spiderwort
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Tradescantia
ohioensis
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Sparkleberry Tree
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Vaccinium
arboreum
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Pipestem Plant
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Agarista
populifolia
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American Witch-hazel
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Hamamelis
virginiana
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Copper Iris
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Iris fulva
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Mariana Maiden Fern
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Macrothelypteris
torresiana
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Red Shouldered Hawk
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Buteo lineatus
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Big Leaf Magnolia
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Magnolia
macrophylla
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Pale Yellow Trillium
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Trillium discolor
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Rice Paper Plant
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Tetrapanax
papyrifer
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Marsh Fern
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Thelypteris
kunthii
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Oakleaf Hydrangea
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Hydrangea
quercifolia
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Painted Buckeye
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Aesculus
sylvatica
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Virginia Jumpseed/
Knotweed |
Persicaria
virginiana
'Lance Corporal' |
Arborvitae Fern
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Selaginella
braunii
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Mulberry Weed/
Hairy Crabweed |
Fatuoa villosa
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Yellow Flag Iris
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Iris pseudacorus
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Dunson Native Flora Garden
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Christmas Fern
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Polystichum
acrostichoides
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Dwarf Crested Iris
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Iris cristata
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Autumn Bluegrass
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Poa autumnalis
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Virginia Rattlesnake Fern
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Botrypus
virginianus
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Early Meadowrue
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Thalictrum
dioicum
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Black Cohosh
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Actaea racemosa
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Tulip Tree (flower)
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Liriodendron
tulipifera
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Canada Wild Ginger
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Asarum canadense
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Jack-in-the-Pulpit
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Arisaema
triphyllum
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Milkweed vine
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Matelea sp.
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Violet Wood Sorrel
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Oxalis violacea
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Partridge Berry
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Mitchella repens
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Hairy Spiderwort
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Tradescantia
hirsuticaulis
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Green-and-Gold
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Chrysogonum
virginianum
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Cucumber Magnolia
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Magnolia
acuminata
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Golden Ragwort
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Packera aurea
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Fringed Campion
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Silene polypetala
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Goldenseal
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Hydrastis
canadensis
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Atamasco Lily
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Zephyranthes
atamasca
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Broad Beech Fern
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Phegopteris
hexagonoptera
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Doghobble
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Leucothoe
fontanesiana
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Green Dragon Plant
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Arisaema
dracontium
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Foam Flower
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Tiarella
cordifolia
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Chattahoochee Trillium
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Trillium
decipiens
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Barren Strawberry
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Waldsteinia fragarioides
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Mayapple
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Podophyllum
peltatum
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Oriental False Hawksbeard
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Youngia japonica
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Rue anemone
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Thalictrum
thalictroides
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