Spring Ephemerals in the Wissahickon Park

News // April 03, 2024

by Susan Haidar, Environmental Education Planner, Wissahickon Environmental Center (WEC)

If you are walking in the Wissahickon Park during late March to mid-May, you may happen upon some beautiful woodland plants.  These short-lived beauties are called “ephemerals” because most of them disappear before the start of summer.   I think of them as the secret flowers of the woodlands…wait too long to see them and they will be gone!

Ephemerals evolved to grow and bloom before most of the forest trees fully open their leaves.  They capture the energy of the sun while it is available.  The forest floor darkens as the tree canopy leafs out, and the ephemerals’ vegetative parts disappear until the following year.

Ephemerals serve as source of nectar and pollen for early emerging bees and flies.  Many have small seeds containing an exterior coating called an elaiosome that are eaten by ants.  In turn, the ants help propagate the plants since they discard the seed underground after eating the coating!  This process is called myrmecochory.

Most spring ephemerals need the rich, moist soils of the forest floor to thrive.

Unfortunately, in much of our region, these native wild plants are competing with hardy invasive plants for territory.  Since most invasive plants lack a species that eats them, they have an advantage in the battle.  Two of the most aggressive invasives are Lesser Celandine and Garlic Mustard.

Do not disturb or pick spring ephemerals.  They will not grow back easily. Some take years to reestablish themselves.

Here are some of the flowers you may encounter in the Wissahickon Park:

Bloodroot (Sanguinaria canadensis) Bloodroot is an unusual plant, consisting of one lobed leaf and one flower that emerges on a separate stalk often before the leaf. Native Americans made an orange-red dye from its root.  It is a member of the Poppy family and one of the first native flowers to emerge.  Colonies of the plant spread by underground stems called “rhizosomes.”  The leaves persist into the summer.

Spring Beauty (claytonia virginica) This flower has delicate small white blooms with pink stripes and pink stamens. It is also one of the first flowers to emerge. The blossom follows the movement of the sun, changing direction throughout the day.  Spring Beauty is commonly seen in Philadelphia parks.  The solitary bee, Andrena erigeniae, is a specialist pollinator of Spring Beauty.

American Trout Lily, Yellow Trout Lily (Erythronium americanum) This flower has delicate small white blooms with pink stripes and pink stamens. It is also one of the first flowers to emerge. The blossom follows the movement of the sun, changing direction throughout the day.  Spring Beauty is commonly seen in Philadelphia parks.  The solitary bee, Andrena erigeniae, is a specialist pollinator of Spring Beauty

May Apple (Podophyllum peltatum)May Apple is hard to miss.  It has a umbrella like-leaf and only one or two leaves per plant, similar to the Trout Lily.  Only the two-leaved plant will flower, and it will produce just one flower on a stem that emerges between the leaves.  The beautiful white white rose-like flower gives way to a green apple-like seed after pollination that is browsed by Eastern Box Turtles and Deer.  You may see large patches of May Apple, since it spreads by rhizosomes.

Virginia Bluebells (Mertensia virginica) Whole areas of this dazzling plant are found in moist woodlands, including along creeks.  The brilliant, light-blue trumpet-shaped flowers with delicate spring-green leaves are delights to the eyes.  Bumble bees and long-tongued bees are pollinators of Virginia Bluebell.

Wild Ginger (Asarum canadense) Wild Ginger will emerge after some of the early spring ephemerals.  It has heart-shaped leaves and, similar to May Apple, spreads by rhizomes to form a dense area of vegetation.  Its bell-shaped flower with three protruding tips is difficult to spot, being low to the ground and a dark reddish-brown color.  Each flower emerges between the bases of two leaves.  The low hanging flowers attract a type of small pollinating fly as it emerges from the ground.  Its seeds are also dispersed by ants. The plant is not related to culinary ginger (Zingiber officinale), but its rhizomatic structure has a ginger-like taste and was used by Native Americans and early settlers as a spice.  It also has antibiotic properties and was used as a poultice on wounds.

Wood Anemone (Anemone quinquefolia) The Wood Anemome produces one five-petal white flower that closes at night.  Plants with flowers have three sets of leaves, each with three leaflets.  Wood Anemones also spread into large patches by rhizomes.  The plant is called the “Wind Flower,” since the flower trembles in windy conditions; the Greek word Anemone refers to a myth about the wind.  Its seeds are also spread by ants.

Skunk Cabbage (Symplocarpus foetidus) The skunk cabbage is one of the first plants to emerge in the spring.  The flowers appear before the leaves and are characterized by a mottled maroon hood-like leaf called a spathe, which surrounds a knob-like structure called a spadix. The spadix is actually a fleshy spike of many petal-less flowers.  As the flowers mature, the spathe opens to allow pollinators such as flies and carrion beetles to enter and pollinate the flowers.  Jack-in-the-Pulpit is another flower with this structure. Skunk cabbage has a remarkable ability to produce heat; it allows it to emerge and bloom even when the ground is still frozen!  During the winter when temperatures are freezing, the flower buds can warm up to 70 degrees Fahrenheit, which melts the snow around the plant.The leaves of Skunk Cabbage will remain throughout the summer. As it name states, Skunk Cabbage flowers omit an odor offensive to humans, but attractive to flies and beetles that eat decaying animals.  They are the pollinators of the flower.

Jack-in-the-Pulpit (Arisaema triphyllum) This unique flower is a sight to behold!   It has a cup-like structure with an overhanging flap, nicknamed “the pulpit.”  (The pulpit is actually a spathe, like that of Skunk Cabbage.)  Inside is the strange shaped flower whose name is “jack”  (the spadix)!  The plant has several sets of three-part leaflets.  Emerging in mid-April, it remains until late August, unlike the shorter-lived spring flowers.  The fruits are initially green; then turn vermillion red by August.  Jack-in-the Pulpit and Skunk Cabbage are in the Arum family of plants and contain the skin-irritating compound calcium oxalate, which also produces the foul odor.

Trilliums– A few of these amazing plants are found in the Wissahickon.  If you find one, it will be the highlight of your walk!  As the name implies, they have 3 leaf-like structures per plant, 3-sepals, and a 3-petalled flower. Trillium is a genus of plants.  There are 38 species of Trilliums in North America, mostly in eastern states, and the majority located in the southern Appalachians.  Classification is based on whether the flower is attached to a stalk or not (pedicellate or sessile). This beautiful Trillium, Little Sweet Betsy (Trillium cuneatum), is found in the Wissahickon.  The color of the flower is maroon and it is sessile.  Sessile trilliums usually have mottled leaves. The Great White Trillium (Trillium grandiflorum) is considered one of the showiest specimens in our area.  Its flower is on a stalk, so it is pedicellate. Despite their beauty, some Trillium flowers smell of rotting meat, which attracts carrion fly pollinators but not humansTrilliums can spread through rhizomes. Note:  Flower removal is a very serious stress on trilliums.  Picking flowers may result in the death of the plant or, if the plant survives, render the plant unable to flower for, possibly, 7 years!  Removal of leaves may also cause the death of the plant.

Early Spring Invasives:

Two plants emerge in spring that compete with our native species.  They are Lesser Celandine (Ranunculus ficaria) and Garlic Mustard (Alliaria petiolata).

Lesser Celandine is one of the first plants to emerge in spring.  In the Wissahickon, its leaves emerge in late February and it flowers in March.  The plant forms a thick green carpet throughout the forest with delicate yellow flowers.  Due to its early emergence and its ability to easily spread by its loose root tubers, it crowds out native spring ephemerals.  This plant was introduced from Eurasia and is considered one of our most problematic invasive plants.

Garlic Mustard was also an accidentally-introduced plant from Eurasia.  It is a tall plant that out-competes the natives.  You can identify it by its toothed leaves and small white flowers.  Garlic Mustard is easy to pull, so feel free to pull it out by the roots, hence keeping it from spreading.  And you can add the tasty, mustardy leaves to your salad, or make them into a pesto sauce!  Create a pulling contest with your friends or kids:  Who can pull the most?  Remember, you will be doing a favor to our native plants!

For more information of spring ephemerals see the following sources:

https://www.bbg.org/gardening/article/native_spring_ephemerals (Brooklyn Botanical Gardens)

https://www.wildflower.org/collections/collection.php?start=0&collection=ss_02&pagecount=10&pagecount=25 (Ladybird Johnson Wildflower Center)