Friday, March 28, 2014

March 27 2014 Ramble Report

Over a dozen people braved the frigid morning temperature to participate in this week's Nature Ramble.

The photos illustrating today's post were selected from Don Hunter's facebook album. The pictures of the Bloodroot elaiosome and the Yellow Jessamine flower types are mine.
We had two readings today, the first recommended by Emily's sister, Jackie Elsner, and read by Hugh Nourse and the second was read by Don Hunter. You can find both readings here.

Sandra Hoffberg is one of our Nature Ramblers. She is a doctoral student in Genetics at UGA, studying the invasive plants Kudzu and Wisteria. She would like to enlist the help of volunteers in determining how long Wisteria patches can persist in the southeast. I'll let Sandra herself tell you about her project and request at this link.

Our route today was to take the White trail from the parking area to the Dunson Native Flora Garden. From there we proceeded down the power line ROW to the river and then turned right on the White trail to see the freshly discovered Harlequin plants. Those seen, we returned to the ROW and walked up the hill toward the second fence to see if the Serviceberry was still in bloom. Then we returned via the White trail.

Many of the flowers we saw blooming in the Dunson Garden last week were still blooming today, so I'll focus on the plants that have started blooming this week.

Bloodroot seed with elaiosome

Johnny-jump-up seeds with elaiosomes
As we walked down the White trail from the parking lot we noticed several Trilliums in the natural area. Since Trilliums do not naturally occur in the SBG these must have wandered over from those in the Dunson Garden. How they got here from there is a fascinating story. Many of the spring ephemerals (those wildflowers that bloom early in spring before the canopy closes) produce seeds that have a "food body." (The botanical term for the food body is elaiosome -- pronounced: E-lie-o-soam.) The elaiosome is made of fat and protein and is quite a tasty snack for ants. When an ant forager discovers a seed with an elaiosome it carries it back to the nest where the elaiosome is removed and eaten by other ants. The seed itself is carried out of the nest and dumped on the ant refuse pile, a rich environment for germinating seeds. So many spring ephemerals are dependent on ants for dispersal and colonization of new places. The next time you see a Bloodroot or Trillium thank an ant!

Perfoliate Bellwort
We found two very small Perfoliate Bellworts with flower buds.

Dwarf Iris has produced some early shoots, but no buds are visible. Wood poppies were up in abundance and blooming.One unusual Trillium with uniformly green leaves (no mottled pattern) was seen. Shooting Stars are larger, but still not blooming.

Dutchman's Breeches
Very small Dutchman's Breeches had a few of their unusual-looking flowers.

Sharplobed Hepatica
The Sharp-lobed Hepatica continues to produce flowers.

The small Pawpaws that we saw flower buds on last week may be mislabeled. The signage identifies they as Asimina triloba, but they are probably A. parviflora (Dwarf Pawpaw or Small-flowered Pawpaw). This information is courtesy of Ellen Honeycutt who pointed out that A. triloba never flowers at such a small size and that its flowers are much larger. By the way, if you haven't visited Ellen's blog, Using Georgia Native Plants, you owe it to yourself to do so. 

Halberdleaf Yellow Violet
Halberdleaf Yellow Violet is blooming.

After leaving the Dunson Garden we proceeded down the power line ROW towards the river. Along the way we found the usual "weeds" growing in the disturbed area next to the path: Hen Bit, Purple Dead Nettle, Gill-over-the-ground (Ground Ivy), and Field Pansy (Johnny Jump Up). For pictures of these plants check out last week's Ramble Report.

In the marshy area between the fence and river we found some kind of cress growing, but no one was able to identify it with certainty.

Indian Strawberry

Yellow Fumewort or Harlequin
Turning right on the White trail we found Blue Speedwell and Indian Strawberry in bloom, as well as our destination plant, Yellow Fumewort, or Harlequin, in bloom. Hugh and Carol first found this plant in the garden a number of years ago but it then disappeared, so it was exciting to see it had reappeared today.

Boxelder flowers with developing seeds
At the river's edge nearby a large Box Elder was in bloom.

Serviceberry flowers
Having found our target we returned to the ROW and went up the hill to see if the Serviceberry was still in bloom. Serviceberries are among the earliest blooming shrubs/trees in the woods and their blossoms don't last very long (as mentioned in the Byron Herbert Reece poem Hugh read at the start of this ramble). On the way up the hill we found the Bluets blooming in profusion, a few Green and Gold in flower and the Redbud filled with their delightful pinkish-red flowers. One of the Redbuds has suffered an infestation of mites that feed inside the buds, transforming them into dark, brittle galls. Further up the hill we passed the lichens that grow on the very poor subsoil exposed on the embankment and then found the Serviceberry. It had lost many of its petals but there were still many intact flowers. Probably by next week only the developing fruit will remain. (The difference between a Serviceberry and a Pear is in the width of the petals. Notice how narrow they are. Those of a pear tree are much fatter and rounded.)

Cedar Apple Gall
On the way back down the hill, where the White trail crosses the ROW we found a small Red Cedar, infected with Cedar Apple Rust. This is a fungal infection that begins with a brownish-orange swelling on the stem. This gall increases in size and then sprouts dark brown horns. When it matures the horns exude orange, gelatinous tentacles that release spores. The spores drift through the air and, if the land on a suitable host plant , develop into a rust infection. This rust, in turn produces spores that can infect Red Cedars. It is significant that the cedar we found is growing in proximity to a cherry tree, because the alternate host of the Cedar Apple Rust fungus is a plant in the Rose family (Apples, Cherries, Plums, etc.) We'll watch the Cherry in the future to see if it develops signs of rust infection.

Yellow Jessamine, long style form

Yellow Jessamine, short style form

Close to the Red Cedar and scrambling over weeds and small shrubs is a vine of Yellow Jessamine, currently bearing several yellow flowers. Hugh pointed out that Yellow Jessamine has two different flower forms. One type has a short style and very long stamens; the other has the reverse condition, a long style and very short stamens. A single plant has one or the other type of flowers, but never both. This peculiar floral difference is increases the likelihood of cross-pollination. When a pollinator like a bee enters a long-styled flower it gets pollen deposited on its head as it seeks nectar at the base of the flower. If it then enters a short styled flower the pollen on its head will be transferred to the short styles at the bottom of the flower. (Actually, it gets transferred to the stigmas at the end of the styles.)Similarly, pollen from a short styled flower will be deposited on the back of the bee, not the head; this pollen can only be transferred to the stigma of a long-styled plant. Why is cross-pollination favored? It avoids the inbreeding that would occur if the plant were to self-fertilize.


No comments:

Post a Comment

Post a comment