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 Linda
Chafin.
30 Ramblers met today.
- Emily announced that next Wednesday, 9:00 a.m., at the SCNC, Allison Huff will lead a birdwalk for the First Wednesday Walk. Bring your binoculars! Lots of other stuff to see, too. Coffee and snacks afterward.
- Gary announced the second annual Winterville Tree Tour, April 14th. It will be followed by a panel discussion on invasive plants in urban forests. Gary is on the panel. Two modes of control will be discussed, goats and sheep, as well as herbicides.
Today's reading: Bob Ambrose
recited one of his new poems, On the First Wave
of Spring.
Today's Route:
We left the entrance plaza at the Visitor Center and headed down the
walkway through the Lower Shade Garden and then into the Dunson Native Flora
Garden, where we spent most of our time.
We returned back to the Visitor Center and gathered at the Cafe Botanica
for the social hour.
 | |
| Cross-vine leaves and tendrils |
Cross-vine is one of
our most beautiful native vines, with its deep orange flowers that have yellow
throats. Lots of cultivars of Cross-vine are in the horticultural trade, some
with solid orange or red flowers. I always thought the name came from the two
leaves, each with two leaflets, that are arranged opposite each other along the
stem. But it turned out that the name comes from the pith, where wedges of
phloem tissue are arranged in a cross shape (visible only if you make a cross-section
of a fairly large vine). More information can be found here.
 |
| A cross-section view of the stem of a crossvine; the source of the common name is self-evident. Photo by Eugene Wofford courtesy University of Tennessee Herbarium. |
Vines in general are plants
that want to be high in the canopy, where the sun and the pollinators are, but
they don’t want to invest a lot of resources into laying down rigid wood like
trees do (forgive the anthropomorphism!). So, they use a variety of means to
attach themselves to trees that lift the vines skyward as they grow upward
together. In the case of Cross-vine, small twining tendrils arise between the
two leaflets, attach themselves to trees, fences, or other vertical surface and
head to the sun. The tendrils are actually highly modified leaves, so in an
evolutionary sense the leaves have three leaflets, one extremely adapted to
climbing.
Lower Shade
Garden:
 | |
| Piedmont Azalea flowers |
Piedmont Azalea is one
of the many beautiful native azaleas that flower in the early spring in Georgia.
This particular plant has white flowers, but most Piedmont Azaleas have pink
flowers.
 | |
| Stamens (brown-tipped structures) and pistil (with green-tipped stigma) of Piedmont Azalea |
 | |
| Piedmont Azalea pistil; ovary on left, stigma on right, the style in between. Pollen landing on the stigma germinates and a tube containing the sperm grows through the style into the ovary where it fertilizes an ovule. |
The sexual organs, pistil and
stamens, of Azalea flowers project far forward of petals, making it unlikely
that a pollinator like a bumblebee could transfer pollen to another flower. A
recent study showed that the most effective pollinator of these flowers is the
Tiger Swallowtail butterfly. The big surprise was how the pollen was carried –
not on the body of the insect, but on the wings! When a swallowtail sips nectar
from an Azalea flower it hovers in front of the flower and its flapping wings
brush against the projecting stamens and stigma (the end of the pistil that
receives pollen). The same study showed that bees were ineffective as
pollinators of Azaleas. The researchers enclosed Azalea flowers in a cage of large
mesh chicken wire that excluded large butterflies but not bees. The uncaged
control plants set seed while the caged plants produced little.
 | |
| Variegated Solomon's Seal |
Variegated Solomon's Seal – This species of Solomon’s Seal is a non-native plant from Eurasia,
planted here in the Shade Garden for its showy variegated leaves and red stems.
Like our native Solomon’s Seal, its flowers dangle in pairs on thread-like
stalks that arise in the leaf axil (the angle between the stem and the leaf).
It’s a cultivar named, appropriately, ‘Variegatum’ for its two-tone leaves.
‘Tis the season for Trilliums in the Dunson Native Flora
Garden! Georgia has the most number of trillium species in the country – 23 at
last count, with at least one new species waiting to be described.
Trilliums come in two forms:
one form has solid green leaves and flowers held at the tips of stalks; the
other form has mottled leaves (with 3-5 shades of green ranging from silvery to
dark Kelly green) and flower that sits directly on the top of the stem,
surrounded by the three leaves. All trilliums (except for the occasional mutant!),
have three leaves, three sepals, three petals, six stamens, and three-parted
ovary/fruit. We have both stalked and unstalked trilliums growing in Dunson,
gathered from all over the state, some very common, some very rare.
 | |
| Chattahoochee Trillium |
The Chattahoochee Trillium, native to SW Georgia, is still in fine
form, with its long stems and mottled leaves bearing a central silver stripe.
 | |
| Spotted Trillium |
Another Coastal Plain trillium,
Spotted Trillium, resembles
Chattahoochee Trillium, but its leaves are less mottled and the dark maroon
petals are narrow, so that if you peer sideways into the flower, you can see
the maroon stamens with their yellow pollen sacs.
 | |
| Sweet Betsy Trillium |
Sweet Betsy Trillium,
also with mottled leaves but without the silver stripe, has shorter stems and
is native to north Georgia, including the Piedmont.
 | |
| Trailing Trillium |
Trailing Trillium
looks a lot like Sweet Betsy – but without a stem! Its leaves seem to sit
directly on the leaf litter, but if you look underneath, you’ll see a very
short, curved stem. It’s found mostly in NW Georgia, in areas where limestone
bedrock has produced “sweet” soils.
 | |
| Lance-leaf Trillium |
Lance-leaf Trillium is
another stalkless trillium but, compared to the three above, is diminutive.
It’s narrow, pointed leaves give it both its common and scientific name. The
flower is maroon and the petals are narrow, revealing the stamens. It’s another
limestone-loving plant, found in high pH soils in NW Georgia, near the Fall
Line, and in SW Georgia.
 | |
| Georgia Dwarf Trillium |
 | |
| Persistent Trillium |
Two very rare trilliums are in
flower now; both are quite small and have stalked flowers: Georgia Dwarf Trillium, found only in NW Georgia, has narrow, solid
green leaves and a white flower at the end of short stalk. Persistent Trillium
(known locally as Edna's Trillium) has wider oval leaves and also a white
flower. Both patches of these species had plants with pinkish flowers – the
older, fading flowers turn pink.
Dunson Native Flora Garden:
 | |
| Perfoliate Bellwort |
Perfoliate Bellwort is
one of two species of Bellwort in Georgia that have ‘perfoliate’ leaves, leaves
that are fused around the stem so that it looks as though the stem is
perforating the leaf.
 | |
| Green-and-Gold |
Green-and-Gold is one
of a handful of Aster family plants that flower in early spring. I think of
this family as coming into its own in the late summer and fall, but Green-and-Gold
and Golden Ragwort (not to mention the Daisy Fleabanes) are pretty spectacular
reminders that this plant rules almost year-round.
Spanish Bluebells, a
showy part of the Dunson Garden flora, is actually a European native that just
won’t go away.
 | |
| Lion's Paw variable leaves |
Lion's Paw gets the
award for the greatest number of different leaf shapes, ranging from triangular
to heart-shaped to shallowly lobed to deeply divided into 3-5 segments, all in
a single patch. It won’t flower until late summer and fall, but its leaves are
a source of confusion throughout the growing season.
 | |
| Tripartite Violet |
Tripartite Violet is
one of our yellow-flowered stemmed violets. Usually the leaves have 3-5
segments but occasionally the leaves are heart-shaped. Common Blue Violet, a
stemless violet, is found scattered throughout Dunson in both purple and white
flower color morphs.
Youngia, or Oriental False Hawksbeard, is increasing in invasiness, showing up everywhere from rich gardens like Dunson to cracks in sidewalks. It’s an annual so if you can’t get it out of the ground, just breaking the flowering head off the stalk will stop that particular plant from spreading its seeds.
Note added April 3: Gary Crider investigated the best method to control Youngia by consulting Eric MacDonald. His response was:
I can say from experience that breaking the stalk would be a
short-term, temporary fix. The plant will respond by sending up several
new stalks. And if you break those, it will send up more new stalks. Like
other plants of this sort, it also has the ability to "learn." For
example, following repeated mowing with a lawn-mower, the plant will send up
tiny flower stalks that are only a few inches high -- tall enough to complete
the reproductive cycle, but not tall enough to get cut by the next pass of the
mower.
It's popping up all over the place. I'm concerned about what that might
mean in terms of management responses, but we're also probably early in the
invasion process, so there are lots of uncertainties. It is a cool season
annual that is usually gone from the landscape by mid-summer. But a single
plant can produce 100s of tiny seeds. Then, the progeny emerge anytime from
late fall to spring, with spring being the peak.
One of the main seed sources for hawksbeard at our Tanyard site is the
mowed "lawn" on the other side of the fence. It is growing so thickly
along the base of the parking deck, that I think I might try to spray it with
roundup.
 | |
| Carolina Spring Beauty |
Carolina Spring Beauty
is one of the early spring wildflowers. As such, it is pollinated by insects
that are active in the cool days of early spring, mostly bees and flies. But it
has an unusual pollinator, a small bee called the Spring Beauty bee. Unlike
other bees it specializes in only one plant, Spring Beauty, and is totally
dependent on its pollen, the source of food for its larvae. When the flowers
stop blooming the bee dies and its larvae complete their life cycle and will
not emerge until spring the following year, just in time to gather pollen from
the Spring Beauties again.
 | |
| Early Meadow Rue female plant with pistillate flowers |
 | |
| Early Meadow Rue male plant with staminate flowers |
Early Meadow-Rue is an
example of a plant where the female flowers and the male flowers occur on
separate plants, a condition known as “dioecious” – which translates as ‘two
houses.’ Plants have developed a number of strategies to prevent
self-pollination (inbreeding) and to promote cross-pollination. Dioecy is the
ultimate example of that: the female and male reproductive parts are held on
different plants, forcing a mixing of genes when the gametes unite. Only about
6% of flowering plants have adopted this method of insuring cross-pollination.
It’s a risky strategy: what if there is
no plant of the other sex within pollen-dispersal range? Perhaps that’s why many
dioecious species are wind-pollinated.
Dimpled Trout Lily –
We have two species of Trout Lily in Georgia: American Trout Lily and Dimpled Trout Lily, both found in the
Georgia Piedmont. American Trout Lily petals have tiny “ears” at the base of
the three innermost petals, and its fruits have a flat or rounded top. Dimpled
Trout Lily petals have no ears, and its fruit has a tiny depression (dimple or
navel, as you wish) at the tip.
 | |
| Dwarf Crested Iris |
 | |
| Dwarf Iris |
Dwarf Crested Iris and
Dwarf Iris are very similar, but
note the white ridges (or crest) on the bright blue sepals of the Crested Iris
flower. The Dwarf Iris has a showy yellow patch on the sepals, but no ridges.
Both serve to draw the attention of bumblebees which follow the colorful patch
to the nectar source.
 | |
| Rue Anemone |
Rue Anemone is one of
the very first wildflowers to appear at the Botanical Garden, usually on moist
lower slopes and stream terraces. Its showy white flowers have – surprise! – no petals. The showy parts of the flower
are actually sepals that have evolved to perform the function of petals–attracting
pollinators.
 | |
| Shooting Stars |
Shooting Stars are
just spectacular, there’s no other word for it. Those backswept petals! Those
shooting stamens! Those red and gold accents! The tall graceful stem! And the
traditional genus name, Dodecatheon,
is pretty cool too. It comes from the Greek word dodeka, meaning twelve. Pliny, the Greek philosopher, assigned that
name to spring flowers he believed to be under the protection of the 12
principal gods of the Greek pantheon.
Woodland Phlox is the earliest
of our many phlox species to bloom. Its flowers range in color from
pinkish-purple to a true, sky blue.
 | |
| Mayapple flower |
As with many of our perennial
spring wildflowers such as Trout Lily and Trillium, Mayapple flowers appear only on mature (6+ years old) plants. A
mature plant will have a forked stem and two leaves (one per stem). The flower
emerges from the angle between the two stems.
Foamflower is just
coming into flower and, true to its native habitat, it seems to show up among
rocks in the Dunson Garden. In the wild, look for it along rocky streamsides
and lower slopes.
Virginia Bluebells are
on their way out. There are many fewer pink buds and many more of the fully
open vivid blue corollas visible now; many plants have already gone to fruit.
The softly green leaves will persist for a while longer, then disappear along
with all the other spring ephemeral plants till next March.
 | |
| Barren Strawberry |
Barren Strawberry, a
rare species throughout its range in Georgia, Alabama, and South and North
Carolina, is in full though inconspicuous flower. A member of the Rose family,
it produces a dry, seed-like, inedible fruit, hence the common name.
Seersucker Sedge is
one of the few easily identified sedges; its leaves are up to an inch wide and
have three prominent veins that give the leaf a pleated or seersucker look. The
bracts that make up the small, slender, male flower cluster are also relatively
showy and dark brown to maroon in color.
SUMMARY OF OBSERVED SPECIES:
Crossvine
|
Bignonia
capreolata
|
Piedmont Azalea
|
Rhododendron
canescens
|
Star Magnolia
|
Magnolia stellata
|
Yellow Trout Lily
|
Erythronium
americanum
|
Variegated Solomon's Seal
|
Polygonatum
odoratum 'Variegatum'
|
Sweet Betsy Trillium
|
Trillium cuneatum
|
Chattahoochee Trillium
|
Trillium
decipiens
|
Perfoliate Bellwort
|
Uvularia
perfoliata
|
Green-and-Gold
|
Chrysogonum virginianum
|
Spanish Bluebells
|
Hyacinthoides hispanica
|
Lion's Paw
|
Prenanthes
serpentaria
|
Golden Ragwort
|
Packera aurea
|
Three-parted Yellow Violet
|
Viola tripartita
|
Oriental False Hawksbeard
|
Youngia japonica
|
Carolina Spring Beauty
|
Claytonia
caroliniana
|
Early Meadow-Rue
|
Thalictrum dioicum
|
Wood Spider Lily
|
Hymenocallis sp.
|
Dimpled Trout Lily
|
Erythronium
umbilicatum
|
Dwarf Crested Iris
|
Iris critata
|
Violet Wood Sorrel
|
Oxalis violacea
|
Georgia Dwarf Trillium
|
Trillium
georgianum
|
Rue Anemone
|
Thalictrum
thalictroides
|
Squirrel Corn
|
Dicentra
canadensis
|
Golden Ragwort
|
Packera aurea
|
Trailing Trillium
|
Trillium
decumbens
|
Shooting Stars
|
Dodecatheon
meadia
|
Dwarf Iris
|
Iris verna
|
Woodland Phlox
|
Phlox divaricata
|
Mayapple
|
Podophyllum
peltatum
|
Star Chickweed
|
Stellaria pubera
|
Hammock Spider Lily
|
Hymenocallis occidentalis
|
Dwarf Paw Paw
|
Asimina
parviflora
|
Foamflower
|
Tiarella
cordifolia
|
Allegheny Spurge
|
Pachysandra
procumbens
|
Common Blue Violet
|
Viola sororia
|
Leatherwood
|
Dirca palustris
|
Virginia Bluebells
|
Mertensia
virginica
|
Lance-leaf Trillium
|
Trillium
lancifolium
|
Barren Strawberry
|
Waldsteinia
lobata (=
Geum lobatum)
|
Persistent (Edna's) Trillium
|
Trillium
persistens
|
Spotted Trillium
|
Trillium
maculatum
|
Running Cedar, Ground Cedar
|
Lycopodium
digitatum
(= Diphasiastrum digitatum) |
Seersucker Sedge
|
Carex plantaginea
|
