The Farmscape Ecology Program * KYPP Nugget 18: 5 May , 2010


KYPP Nugget: Spring Flowers


Spring Flowers: Background Exploration

Photo Essay - Let us begin with a collection of photos to illustrate some of the plants mentioned:

Broad-leaved Sedge (Carex platyphylla) is one of our "evergreen" forest sedges. Note how last year's leaves begin to desintegrate from their tips at the end of the winter, just as new spring growth begins to emerge from the center of the plant.


Hepatica has the same strategy: last year's leaves, which stayed green all winter, begin to desintegrate as the plant flowers.


Gaywings or Fringed Polygala (Polygala paucifolia), another spring flower with evergreen leaves.


Trout Lily (Erythronium americanum), whose brown-speckled leaves are among the first emerging in early spring from underground tubers.


Jack-in-the-Pulpit (Arisaema triphyllum) is a plant that changes sex with age and condition. Young or malnourished plants are males, producing only pollen in the many tiny flowers arranged around the base of the central column inside the "pulpit". Older individuals growing in good soil become females after a few years. Their tiny flowers, which are also arranged around the base of the central column only contain ovaries and do not produce pollen. After pollination, they develop into seeds packed into red berries which are exposed in fall when the "pulpit" has whithered.


The native Wild Ginger (Asarum canadense) is a totally different plant from the tropical gingers whose spicy tubers are sold fresh, candied, or as dry powder. Its root has a "gingery" taste, but is not worth the harvesting of this rare plant which only occurs in isolated small colonies, usually associated with calcium-rich bedrock outcrops or in floodplains. Note the peculiar, triangular flower emerging from the base of the leaf. Its color and putrid smell attract flies as pollinators.


Marsh Violet is one of our most common blue violets, found in wet meadows, seepy areas, and in floodplain forests.


The rare Canada Violet is an example of a white-flowered violet. The few places we know it from in the County are all associated with calcium-rich bedrock.


The Yellow Forest Violet is a relatively common violet of rich forests. All violets, like many other spring flowers, have their seeds equipped with nutrient-rich appendices ("elaiosomes") that are eaten by ants, who disperse the seeds in the process. Violets have two slick back-up systems in case a cold or rainy spring does not allow for pollination and seed production in their flowers. They develop a second set of "cleistogamous" flowers who  remain underground, never open, and are able to self-pollinate and develop seeds in case of emergencies. Violets are also able to flower again in fall.


Dutchman's Breeches (Dicentra cucularia) is a rare native relative of Bleeding Heart.


Blue Cohosh (Caulophyllum thalictroides) is one of our rarer species that occurs only in old woodlots with rich moist soil.
5/5 column: "Spring Flowers"

by Claudia Knab-Vispo

   Spring flower season is certainly one of the most exciting times in the year for anybody walking the woods with an eye for plants. It starts quietly, almost imperceptibly, as soon as the snow has melted, with the unexpected discovery of something green on the forest floor. There are a few plants actually hanging in there all winter, keeping their leaves green, ready to put in a few hours of photosynthesis, conditions permitting, throughout the cold season. Christmas Fern and Evergreen Wood Fern, most mosses, but also certain woodland sedges are “evergreens”. None of these would qualify as spring flowers per se, but they are welcome early signs of life on the newly snow-free forest floor otherwise covered by brown leaf litter. Sometimes, these common evergreens are joined by other small evergreen plants that actually do produce lovely spring flowers. The early Hepatica with its unassuming flowers of white, pink or bluish petals; Trailing Arbutus with its paired, pinkish-white, trumpet-like flowers of heavenly fragrance; Fringed Polygala, or Gaywings, with its small clusters of upright dark green leaves and almost pea-like, deep pink flowers; and finally, Wintergreen, its leaves looking so similar to those of Gaywings, but easily distinguished by the “wintergreen” smell if crushed, and, once they appear, the little white bell-shaped flowers. In swamp forests and along some streams, the peculiar hoods of Skunk Cabbage grow under the snow and are the first green to be discovered on an early spring walk. If you don’t see them, you smell them! Not usually thought of as a spring flower, Skunk Cabbage is actually one of the first plants to bloom, its inconspicuous flowers arranged on a cone-shaped structure protected by the hood.

   Yet, most of our typical spring flowers rest all winter out of sight, withdrawn into bulbs or tubers, not risking so much as a peek before spring is underway for real. And then, one happy day, their tentative sprouts begin to emerge. The very first around here tend to be the brown-speckled, shiny leaves of Trout Lily colonies (also known as Fawn Lily, or Dogtooth Violet, or Adder’s Tongue – this multitude of seemingly unrelated common names for our spring flowers is sometimes a bit maddening, but don’t despair, pick one you remember and stick with it!).  Some of the Trout Lilies in each colony produce a pair of leaves and a flower stalk bearing a single, dangling bell of 6 yellow “petals”. Another very early bloomer in our woods is the enchanting Bloodroot. While Trout Lily is gregarious and many of its leaves stay without flowers each year, Bloodroot grows more “here and there”, each flower bud emerging from within the protection of a single leaf wrapped around the flower stalk like a cloak. The white Bloodroot flower opens for a single day, the peculiarly-shaped leaf unfolds and then continues to increase in size, while the seed capsule ripens.

   After the Trout Lily and the Bloodroot, where one can still cherish each individual flower, nature’s spring flower display tends to explode into a multitude of colors and forms, leaving the observer almost dizzy in the attempt to keep track: Trillium, Jack-in-the-Pulpit, Wood Anemone, Wild Ginger, Toothwort, a confusing variety of violet species with flowers in shades of blue, white, and yellow, Solomon’s Seal, Bellwort, Spring Beauty, Dutchman’s Breeches, and Blue Cohosh, to name but a few…

   While all the species mentioned above do grow together on a hill here in Harlemville and many of them can also be observed in Public Conservation Areas, such as Hand Hollow, Round Ball, High Falls, or Drowned Lands Swamp, nature’s spring flower display is not equally diverse and abundant everywhere. Spring flower communities tend to be most striking on deep, moist, nutrient-rich soils. These are often found in floodplain forests, but also at the bottom of hills, and around outcrops of calcium-rich rocks.

   Furthermore, researchers throughout the Northeast have found that forests never cleared for agriculture (but yet perhaps selectively cut or occasionally grazed) often harbor richer native wildflower communities than neighboring secondary forests growing on former fields or pastures. Our past studies of floodplain forests in this region confirmed that. This year, we are initiating a study of old farm woodlots, to see if ancient upland forests in our County also have a consistently higher native wildflower diversity than adjacent secondary forests, and to look into possible reasons why that might be so. Are the soils in secondary forests just not quite as rich in moisture and nutrients? Do the seeds have a hard time getting to and establishing themselves in formerly cleared areas? Another interesting question we hope to address is to what degree plant and insect diversity go hand in hand.

   These are just some thoughts as I wander through the forests and ponder why a certain species of wildflowers maintains a patch over here but has not yet been seen over there… Maybe the wildflowers can serve as indicators that point to a generally richer, more complex network of life in the old forest woodlots? This would be important to know, because islands of ancient forest are so easily overlooked in today’s landscape where they are surrounded by a sea of secondary forest.

   Interested in participating in the woodlot study? If you’re on farmland, think you have an old woodlot, and would like to learn more about its ecology, please let us know.

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Bloodroot, one of the earliest and most distinctive spring flowers in our County.


Spring Flowers: Background Exploration (cont.)

Old Woodlots - the following pair of aerial photos of the same place in Canaan illustrate the idea of "old woodlot islands" (clearly discernible on the 1940s aerial photo) becoming integrated in a "sea of successional forest" by 2009.


We call these forest remnants "old woodlots" or "ancient forests" and wish to emphasize that they are not "pristine" or "old-growth" forests. Most of these forest remnants have been used for selective timber harvest and might also have been grazed by lifestock in the past. Their species composition has certainly been influenced by human activity. Yet, they often retain a different quality because they have never been completely cleared and their soils have not been plowed.
Old woodlots often have a more rugged surface than successional forests growing on formerly plowed land, maintaining a distinct "pit-and-mound" pattern created by uprooted trees and the resulting holes and hills. Their soils maintain distinct layers (horizons) with most organic matter occuring near the surface.
Depending on their logging history, old woodlots might have much bigger trees than the surrounding succesional forest and their canopy tends to be composed of a different set of tree species. Finally, there seems to be a set of native forest herbs, many of them spring ephemerals, which occur exclusively or in much higher densities in ancient forests. 

Resources:

Bellemare,  J., Motzkin, G., and D.R. Foster. 2002. Legacies of the agricultural past in the forested present: an assessment of historical land-use effects on rich mesic forests. Journal of Biogeography 29: 1401-1420.

Farmscape Ecology Program. 2011. Natural and Agricultural Observations from in and around Hawthorne Valley. A weekly blog posted at http://hvfarmscape.wordpress.com/

Flinn, Kathryn M. and M. Vellend. 2005. Recovery of forest plant communities in post-agricultural landscapes. Frontiers in Ecology 3(5): 243-250.

Sanders, Jack. 2003. The Secrets of Wildflowers. A Delightful Feast of Little-Known Facts, Folklore, and History. Lyons Press, Guilford CT. 304p.