Spring is happening all around us! It’s very hard to keep up with the pace of change.The daffodils are are in full bloom, and the forsythia are in various stages of flowering. Entire neighborhoods and forest hollows are turning yellow overnight. The lilacs are leafing out along with the willows and the plum trees, and, yes, alas, the grass is continuing to grow.
Deborah and I went up to Harrison Hills Park on Wednesday afternoon to take a walk on their Wetlands Trail. The Wetlands Trail loops around and over a set of small streams that run through the north part of the park. In all of the creek-side low spots large numbers of the distinctive, striped, reddish-purple spathes of skunk cabbage were visible. The spathe houses the skunk cabbage flower and as I previously discussed is able to generate its own heat and survive and attract pollinators even in early February. Most of the spathes were still intact although a few were starting to crumble away. Almost all were surrounded by 8 or 10 inch long, bright green leaves. These leaves will grow rapidly in the coming weeks to make an interconnected mass of vegetation.(all images: D. Sillman)
The yellow, dandelion-like flowers of coltsfoot (Tussilago farfara) are abundant along the Wetlands Trail. This is also an introduced species from Europe and Asia and probably came into Western Pennsylvania with the first European settlers. It is a plant with a number of traditional, medicinal uses but is a potent source of alkaloids that can be toxic. Coltsfoot is unusual in that it flowers long before it sets its leaves. So, if you see a yellow, dandelion-like flower and no surrounding leaves, it’s probably coltsfoot! Coltsfoot is classified as a alien exotic plant and can be an invasive “weed.” It is a welcome blast of yellow, though, in these still very brown days of early spring.
Raspberry canes grow both as isolated plants and also in dense thickets along the sides of the trail. Tiny green leaves are just starting to open on the thorny, purple canes. This section of the trail should have quite a bit of fruit in mid to late June. Good for the birds and very good for passing hikers!
The tiny, white flowers of spring cress (Cardamine blbosa) stand out against the dark brown leaf cover. Many of the expected spring flowers, though, are just starting to show their leaves. We recognize the new leaves of Dutchman’s breeches (Dicentra cucullaria) and look forward to their beautiful, white flowers.
Along the return part of the trail loop we come upon some of the largest spicebush (Lindera benzoin) plants we have ever seen. The woody trunks of several of the bushes are quite tree-like in girth. The bushes are covered with clusters of small, yellow flowers which we know from our work out on the Campus Nature Trail are exclusively “male” or “female” on individual plants. We have identified and mapped the male and female spicebush plants out on our trail (identifying the female plants by the presence of berries in the late summer) and found that the female bushes tend to be smaller than the males and are more frequently found in the sunnier sections of the trail. We relate these data to energy: the female plant has to put more of its metabolic energy into its fruit (and is thus smaller) and must be able to photosynthesize at a higher rate than the male plants. The spicebush leaves will open in several weeks. I recommend picking one or two of these fresh leaves and crushing them in your hands. Their sweet, aromatic scent is quite refreshing and explains both the common and scientific name of this species.
There are a few insects out on the trail. Several large, bumblebees float past us like miniature blimps. They are a common early pollinator in the spring but must be careful not to get caught too far away from their hibernaculae as temperatures drop in the late afternoon. Tiny, solitary bees and a mixture of even tinier flies buzz about the spicebush and spring cress flowers. We also see one mourning cloak butterfly flying uncharacteristically close to the ground. This has been a very good year for mourning cloaks! We have seen them regularly on our walks in the woods throughout Armstrong, Westmoreland, and Allegheny Counties.
A northern flicker follows us for most of our two hours on the trail. Its distinctive, laughing call echoes throughout the surrounding mixed oak forest. We only occasionally get a glimpse of him flying from tree to tree, but his hammering and calling are always very close by. We also see quite a few robins and hear crows cawing in the distance. More birds, I am sure, will fill in this habitat as spring progresses.
A thunderstorm chases us along the last quarter of a mile of the trail. We get to the car just as the rain begins. A very nice early spring walk with the promise of much more to come!