THIS WEEK at HILTON POND
1-7 May 2006

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SPRINGTIME DYC

We seldom find the first spring wildflowers abloom in open fields. The best place to find them is deep woods, where well-rotted leaf litter on the forest floor provides nutrients and where trees themselves offer shelter from harsh weather that sometimes comes when winter refuses to go away. By late spring, however, trees have leafed out so much that herbaceous woodland plants have trouble gathering enough sunlight to flower--or to attract attention of visually oriented pollinators. It's therefore not surprising that from May onward at Hilton Pond Center, the more likely places to see wild blossoms is in our small tree-less meadows and along roadsides that border the property. And come August and September, it seems the majority of those open-area flowers are DYCs or DWCs--"Darned Yellow (or White) Composites," the bane of the field botanist. Composite flowers ARE difficult to identify--especially in late summer when there are so many that look so much alike--so we were grateful we had only a few springtime species to choose from when trying to identify a DYC this week at Hilton Pond.

All text & photos © Hilton Pond Center

Composite flowers--classified in the Asteraceae (or Compositae) because their blossoms resemble a starburst--do provide a taxonomic and identification challenge, in part because they make up the largest order of flowering plants. Many of the most abundant and most visible plants of the Piedmont countryside in late summer and autumn are composites--Joe-Pye-Weed, Dogfennel, Boneset, Sneezeweed, Yarrow, Daisy Fleabane, the thistles and true asters, and, of course, Goldenrod--but becoming more abundant in Hilton Pond meadows in recent springs is an eye-pleasing composite with quarter-inch golden-yellow flowers: Small's Ragwort, Senecio smallii.

Small's Ragwort--sometimes classified as Packera anonyma--is found across the eastern third of the U.S. from New York State to Florida, northwest to Indiana (southern counties only), and southwest to Missouri and Louisiana. When we were in central West Virginia this week to speak at Fayetteville's New River Birding & Nature Festival, we saw signs of Small's Ragwort, but phenology at that latitude is a few weeks behind the South Carolina Piedmont and none of the plants were yet in bloom.

Small's Ragwort is definitely a composite, showing two types of flowers--the petal-like structures that are actually sterile "ray flowers" that point pollinators toward the fertile "disk flowers." In the photo above, ray flowers are the flat, elliptical, grooved structures. The disk flowers begin to open from the perimeter, the yelllow-orange bumps at the disk's center being flowers that are not quite ready to produce either nectar or pollen. A magnified view of the centermost flower (below left) reveals every tiny disk flower is a so-called "perfect flower, " each with even tinier pollen-bearing stamens and a pistil. Incidentally, when pollination occurs, the Small's Ragwort flower produces a nutlet that is gray and fuzzy; its genus name Senecio comes from senex, which is Latin for an "old man." (Get the stereotypical connection?) The common name "ragwort" is derived from words meaning "worthless" and "plant," implying that folks thought this species had no value.

Although some composites are annuals or biennials, Small's Ragwort is a perennial that, once it has established a strong root network, sprouts year after year--or at least does so unless the open area in which it grows is overtaken by shrubs or trees through vegetative succession. Historically, Small's Ragwort in the Carolina Piedmont was assured a place to thrive because American Bison and fires maintained grasslands and prairies. These days the only way to keep a meadow open for ragwort habitat at Hilton Pond Center is by using a weedeater every other winter.

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Like many composites, Small's Ragwort has two different kinds of foliage. At the bottom of the stem are so-called "basal leaves" that are somewhat broad and paddle-shaped (above left); these persist in winter and perhaps enable a little photosynthesis ahead of a sudden spring growth spurt when the vertical flower stalk appears (below right)--accompanied by a few very different-looking leaves that are highly dissected along their edges (above right).

Like its flowers, the leaves of Small's Ragwort are also pleasing to the eye, but don't let looks fool you. Many members of the Senecio genus are poisonous plants that cause an ailment known as "seneciosis." For example, Golden Ragwort (S. aureus) and Tansy Ragwort (S. jacobae) are known to contain some combination of liver-damaging pyrrolizidine alkaloids such as jacobine, retrorsine, senecifoline, senecine. Livestock--or humans--that happen to graze on these ragworts can exhibit symptoms including jaundice, cirrhosis of the liver, photosensitization, and central nervous system disruptions such as clumsiness and confusion. It's not well-documented if Small's Ragwort is as toxic--several other related species appear not to contain all the dangerous alkaloids--but we still suggest you NOT include any Small's Ragwort leafy matter in your next Dandelion salad.

While photographing the ragwort we wondered if it might be self-pollinating because we didn't notice any bugs or beetles buzzing about. Turns out this was probably because on our first day in the field skies were overcast with temperatures in the 60s. The next time we explored the meadow with camera in hand the clouds had cleared and morning sun was beaming down on Ragwort flower heads--nearly all of which had at least one tiny insect flitting and foraging. Through our macro lens we could see these were all the same kind of hoverfly--Toxomerus marginatus, the Flower Fly--and each was probing open florets around the perimeter of a ragwort flower disk, lapping up what must have been almost infinitesimally small doses of nectar; female Flower Flies, by the way, are also obligate feeders on pollen, while larvae of both species are predatory on aphids and small caterpillars that might otherwise eat the host plant's flowers or foliage. This particular hoverfly's mouthpart--relatively large and barely able to fit into the floret opening (highly magnified above left)--reminded us of the big, slobbery tongue of a Labrador Retriever.

If Small's Ragwort does contain any toxic alkaloids, it likely wouldn't put any in pollen or nectar to impact on pollinating hoverflies, and we doubt any of our other local browsing fauna are affected adversely by this plant. That's just as well, because as a springtime DYC that CAN be identified, we like having bright-yellow, eye-pleasing Small's Ragwort growing in our May meadows at Hilton Pond Center.

All text & photos © Hilton Pond Center
Hoverfly ID by Mario Ambrosino, Oregon State Univ.


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Thanks to the following fine folks for recent gifts in support of Hilton Pond Center for Piedmont Natural History and/or Operation RubyThroat: The Hummingbird Project. Your contributions allow us to continue writing, photographing, and sharing "This Week at Hilton Pond."



Be sure to scroll down for an account of all birds banded or recaptured during the week, plus other nature notes of interest.


"This Week at Hilton Pond" is written & photographed
by Bill Hilton Jr., executive director of
Hilton Pond Center for Piedmont Natural History.

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BIRDS BANDED THIS WEEK
at HILTON POND CENTER

1-7 May 2006

SPECIES BANDED THIS WEEK:
American Goldfinch--1
House Finch--4

* = New species for 2006


WEEKLY BANDING TOTAL
2 species
5 individuals


YEARLY BANDING TOTAL (2006)
18 species
794 individuals


BANDING GRAND TOTAL
(since 28 June 1982)
124 species
47,376 individuals


NOTABLE RECAPTURES THIS WEEK
(with original banding date, sex, and current age)
House Finch (1)
03/11/05--after 2nd year male


This Week at Hilton Pond
is part of the

OTHER SIGHTINGS OF INTEREST
--Our annual trip to lecture and band at the New River Birding & Nature Festival in Fayette County WV, kept us away from Hilton Pond Center for several days this week, but it's always good to get back to the Mountain State. In its fourth year, the festival drew more than 200 participants from the U.S. And Canada for a week of intensive and enjoyable birding via van, walking trail, river raft, and lounge chair.

--The first fledgling House Finches began appearing at the Center's feeders this week--we managed to trap and band one of them--making HOFIs among the earliest passerine breeders around Hilton Pond. We've also seen a couple of broods of recently fledged Carolina Wrens already this spring. (Still no Ruby-throated Hummingbirds banded locally this year.)

All text & photos © Hilton Pond Center


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Hilton Pond Center for Piedmont Natural History is a non-profit research & education organization in York, South Carolina USA; phone (803) 684-5852. Directed by Bill Hilton Jr., aka The Piedmont Naturalist, it is the parent organization for Operation RubyThroat. Contents of this Web site--including articles and photos--may NOT be duplicated, modified, or used in any way except with the express written permission of Hilton Pond Center. All rights reserved worldwide. To obtain permission for use or for further assistance on accessing this Web site, contact the Webmaster.


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