Round-lobed hepatica appears to bloom over a couple weeks time, with flowers coming and going according to the weather. Rainy, overcast and cooler weather hold back their blossoming.
Like a lot of flowers hepatica blossoms close up at night, too. This daily opening and closing of blooms is probably related to changes in temperature. Springtime evenings are cool and even cold, so perhaps there is some advantage to the plant in keeping the reproductive parts warm by closing up their petals.
The colorful “petals” of hepatica close up around the stamens overnight. The photo above was taken at 11 am and shows the blossoms just opening up in the daylight. Note that the three rounded bracts are visible.
Close-up photo of morning hepatica blooms taken 1 April 2010. The same hepatica flowers at about 6 pm the previous day were fully open (photo below taken 31 March 2010).
On March 31st the Round-lobed Hepatica, Hepatica americana, were blooming strong. I counted 13 hepatica plants on the south east quad, west and south of the original found plant at the moss-covered skinny log. I think I may have been in the woods at the right time to see so many plants. All it takes is a little wind for the oak leaves to cover up the hepatica and hide it from us, so make sure to look well among the leaf litter for it.
The previous two days were cloudy, overcast, windy and rainy. The delicate forest flowers must need at least a little sun to coax their blooms out of hiding. After all, they only bloom once in a year and when they do bloom it’s during the time when there are no leaves on the trees.
Leaf buds are pushing a little on a few trees, like the cherry trees and lilacs, but for the most part the scenery is still drab shades of gray and brown accented with flowering forsythia and star magnolia.
White flowers are opening up on this round-lobed hepatica. It’s an older plant with at least seven leaves and as many flowers. (Click images to see larger view.) Note that the petals are shorter than the bracts under the flower head. Young petals are smaller than the bracts. As the flower matures the sepals get larger until they are about the same length as the bracts.
The true colors of the two blossoms above are pale blue. The waxy surface of the leaves can be seen here as a shiny surface.
In real life the flowers were a much deeper blue to purple color, but the sunlight – and a flash on the closeup images – washed out the color. The afternoon sun shone on the hepatica flowers softly, but the images from my little digital Olympus were overexposed. Can’t wait to get a manual everything camera.
Closeup of light purple round-lobed hepatica flowers. This plant grew at the base of a big oak tree, so it was easy to find it again. Use landmarks around you to re-locate plants that you want to observe throughout the year.
This older hepatica plant, as noted by the many leaves and flowers, has a set of smaller, upright leaves. The upright leaves are not rounded on the edges, but rather pointed or angular and about the same size as the flowers.
Closeup of smaller, upright leaves shows they are taller than the flowers. Why are these leaves held upright? Are they young versions of the mature leaves that overwinter or do they have a different purpose? Several of these smaller leaves are deformed or have been nibbled on. Not many of the larger, rounded leaves are so deformed, but there are a few leaves that are torn or damaged that survive from year to year. Perhaps mammals of the forests that browse on the small leaves help to pollinate hepatica.
Here, we see that ants are likely pollinators of round-lobed hepatica. Note the fuzzy appearance of the flower stems and the tight anthers on the cream-colored stamens that stick out like little lights.
Flowers don’t all blossom at one time. In the image above there are two fully-developed flowers with their petals held out flat, one flower about to open, two with bent heads and flower stalks almost tall enough, and one with a short flower stalk and tighter flower bud. Note the hairy stems and bracts. The hairs are quite long in places, making the flower heads and stems appear fuzzy.
Leaves are hairy as well. Older leaves may lose some of the hairs, which are not as long as the hairs on the flower stems.
When you’re taking a walk in the woods searching for hepatica and other Spring ephemeral flowers, stop every now and then and scan the leaf litter all around you. Look for any bit of green on the forest floor and if there is a well-rounded edge to the leaf inspect it a little closer.
At times you will find the flower poking its head above the leaf litter while the leaves that have overwintered are still under cover. This has led to some field guides to state that hepatica flowers will appear before the leaves do. Actually, the leaves are there too, just not completely visible.
Typical view of hepatica with the flowers sticking above the leaf litter and the leaves hidden below the oak leaves.
Three bracts underneath the flower heads are either green or maroon, hairy, and rounded at the tips.
This plant has two flowers in the bud stage and a young opened flower that appears to be supported by the three maroon bracts beneath the open flower head.
Not all hepatica plants were flowering on this day. I suppose they don’t flower each and every year, or perhaps those without flowers had already bloomed. At the most the plants that I saw had two blossoms full out per plant, some had only one or no flower – at that particular time. A couple plants had already flowered and dropped their petals, while more blossoms are yet to fill out.
The weather has been unusually warm for much of the US East Coast for the past week. The heat continued to rise to 25 degrees or more over the average for this time of the year, which is about 58 degrees. In Millerstown, PA high temperature records of 85, 89 and 89 degrees were set on April 5, 6 and 7. Yesterday, we tied the record at 86 degrees. Then the cold front came through.
It was a fast storm that reset the temperatures down to normal. Winds blew gusty, lightning hit all around us, the power flicked on and off a few times, and finally a soft rain cooled everything off.
The sunny and warmer than usual weather has pushed vegetation growth and flower blooming much faster than normal. Plants grow and flower according to the amount of sunlight received and temperatures experienced. So, it is a combination of warmth and light that will indicate to a plant that the time is right for flowering, or fruiting for that matter.
Higher temperatures will speed up plant growth and as a result the time of flowering can arrive sooner. The opposite may happen during colder than normal temperatures where growth is slowed and blooming delayed.
Additionally, some plants are not sensitive to the amount of light available, so sunlight is not a factor in their blooming time. These plants are called photoperiod-insensitive plants.
A woodland plant blooming earlier in 2010 is Hepatica. We know that hepatica, one of my favorite woodland plants, blooms in very early Spring, before the trees leaf out. That means that hepatica will bloom in Pennsylvania sometime in April, depending also on latitude and elevation. Will weather conditions, which are very quick to change this time of year, dictate the blooming times of hepatica? It seems so, considering that in 2010, with record-breaking high temperatures, we have observed hepatica and other plants blooming much earlier.
Many other plants are also flowering earlier this year. All the plants photographed in the wildeherb links above are blooming now or just past blooming. For instance, the star magnolia has leaves developed already and maybe two blossoms are still hanging on one limb. All the other flower petals have fallen to the ground. Yet, in 2006 the same star magnolia tree was in full bloom on April 11 and no leaves had yet developed.
Tulips, peach trees, ferns, dandelions, and violets all seem to be at about the same development stage now (April 9, 2010) as shown in the April 19, 2006 photos. The one exception is cinquefoil. Its flowers have yet to appear, so perhaps their blooming is dictated more by the available sunlight instead of the prevailing temperatures. A photoperiod-sensitive plant, perhaps.
If the old weather data could be matched up to the images, we might actually be able to document temperature-dependent blooming times. It would be interesting to find out which of the Spring ephemerals are more keyed to temperature than sunlight. That might make it possible to go into the woods at the right times to spy on them!
On a grander scale there are implications here regarding global warming. It’s been documented that blooming has been occurring earlier in the year in some places and for years now. Some are worried that the insects and other pollinators for the early blooming plants might not be in the proper areas to perform their pollinating service at the right time. Insects slumber, birds and bats migrate. During early spring if the plants get way ahead of the pollinators, it could spell disaster for future generations of plants.
At the extreme this raises the question of possible plant extinction due to climate change. Without pollinators in the scenario, these flowering plants won’t be able to reproduce by seed.
April 1st ushered in changes to the scenery around us here in South-central Pennsylvania. Spring blooming plants and trees are really starting to take off and other plants that bloom later in the year are shaking off their winter dormancy.
Forsythia shrubs are blooming in full with the sunshine showing their lemony yellow blooms. The sweet scent of star magnolia blossoms delight the nose from afar. In front yards everywhere you can see the yellow, orange and white of daffodils or narcissus blooms. Bradford pear trees are blooming white and magnolias are starting to open their heavy pink and white flowers.
Greenery of several plants are appearing —
virgin’s bower vine, down near end of lane
mayapple buds emerging an inch or so, only saw two buds
touch-me-nots sprouted all along area where wild rose on lane is being cut back, next to elderberry
One plant that I was a little surprised to see coming up is Bee Balm or Oswego Tea. It was transplanted last year from being in a pot for two years, even overwintering in the pot! I was surprised to see it made it through the winter and didn’t get frozen solid while in the pot. Last Autumn the bee balm was transplanted out back on the west side of the woods before the weather turned too cold to dig. Here, it will get filtered morning sun and full afternoon sun. I wonder if all Monarda are as hardy and survive extreme conditions as well as this Bee Balm.
Coltsfoot is still blooming in places along roadsides in Pennsylvania. Coltsfoot, Tussilago farfara, could be considered a Spring Ephemeral flower, but that term is usually reserved for woodland flowers that have a very short life cycle with a narrow window to bloom.
The Spring Ephemerals only receive enough sunlight to bloom after it gets warm enough in late winter and early spring up until the time when the trees develop their leaves. Once the forest canopy is filled in not enough light gets to the forest floor for these small herbaceous plants to continue flowering.
Typically, you’ll see coltsfoot along the road or trail side where it can get enough sunlight to develop its leaves. The leaves will stick around for most of the summer, so the life-cycle for coltsfoot is too long for it to be considered a true Spring ephemeral, but it does bloom in very early Spring, when the ephemeral flowers are blooming. Coltsfoot is a perennial that will return year after year. (Photos taken 1 April 2010.)
Note that some of the flower heads are stilled bowed down from the night. These flower heads will also rise up once they receive enough sun.