24 September 2021

In late September the most abundant fruits and flowers are often on invasive plants. Some are pretty, some are not.

Clusters of bright red berries look festive on bush honeysuckle (Lonicera tatarica) as they change from green to brown to red.

Porcelain berries (Ampelopsis glandulosa) are beautiful up close in turquoise and purple.

A few porcelain berry flowers are still in bloom.

But step back and the vine’s invasive habits are ugly as it drapes trees and hillsides. Yes, there are a couple of trees under the vine.

Meanwhile, in my opinion mugwort (Artemisia vulgaris) is unredeemable. In June it crowds the sunny edges of trails.

In September it’s tall and gangly with drooping green and brown stems. Are the brown bits seed pods?

No. They are ugly flowers.

Not pretty.

(photos by Kate St. John)

23 September 2021

Tiny purple and white flowers are blooming this month on stems that stand a foot tall in the woods. Unless you know where to look for them, though, you’ll probably never see them. These brown plants match the ground.

Beechdrops (Epifagus virginiana) have no chlorophyll because they are parasitic on the roots of beech trees (Fagus grandifolia). To find the flowers, I find a beech tree(*) then put my head close to the ground and look sideways near the roots.

From this angle beechdrops stand out … barely.

Beechdrops (Epifagus virginiana) bloom from July to December, producing self-pollinating flowers at the base of the plant and cross-pollinating flowers at the top, though some of the top flowers are sterile.

The top flowers are pollinated by the winter ant (Prenolepis imparis) that aestivates underground when its hot and only comes out in cold weather. I imagine that’s why the July-blooming flowers are self-pollinating.

Beechdrops are so dependent on the American beech that their seeds don’t germinate until they detect a chemical signal from the tree.

Beech is really in their name. The genus Epifagus is Greek for epi = On + fagus = Beech.

Literally, on the beech.

p.s. (*)Find a beech tree: American beeches have very smooth pale bark. See this blog post for tips on how to identify them: Winter Trees: American Beech.

(photos from Wikimedia Commons and Flickr Creative Commons license; click on the captions to see the originals)

13 September 2021

Today’s article began with a question asked three times: What is that weed? I couldn’t remember the name even though I knew each was in the knotweed family (Polygonaceae) and that a similar native species was named for Pennsylvania.

On the first question I took a picture in Schenley Park, above. On the second question, Claire Bauerle took a picture at Duff Park, below. My plant and Claire’s plant are both alien but not the same species.

Claire’s plant shows its name on its leaves, a shadowy thumbprint in the center of the leaf.

Lady’s thumb (Persicaria maculosa) is a Eurasian smartweed that first appeared in the Great Lakes region in 1843, has spread across the continent, and is sometimes invasive. The dark thumbprint is a simple way to identify the plant.

My plant is similar but lacks the thumbprint. Not the same species but my photo is not detailed enough for a complete identification. My guess is Oriental lady’s thumb (Persicaria longiseta) a common weed in Asian rice paddies introduced to North America near Philadelphia in 1910 and now found across eastern North America.

The third question was answered on Sunday’s Botanical Society walk on the South Side where we found the smartweed named for Pennsylvania.

Pinkweed or Pennsylvania smartweed (Persicaria pensylvanica) now grows in waste places around the world. Gangly-looking compared to the lady’s thumbs, it has longer stalks, thinner leaves, and fatter, shorter, paler flower heads.

Here’s a single stalk.

It has no flower bristles like those found on Oriental lady’s thumb P. maculata.

All three smartweeds have stems that connect to the stalks at knot-like ochreas. Two of them, P. longiseta and P. pensylvanicum have bristly ochreas, shown below.

Identifying smartweeds is much trickier than I’ve described so I may have misidentified the first two plants.

If I was smart I’d know what to look for and take better pictures to key them out.

(photos by Kate St. John and Claire Bauerle)

p.s. Three range maps which might not work in Chrome: P. maculosa, P. longiseta, P. pensylvanica

31 July 2021

In late July field flowers bloom while others develop seeds.

The photo at top of oxeye or false sunflowers (Heliopsis helianthoides) was supposed to be a documentation photo so I could study the leaves. Can you find the milkweed bug on one of the flowers?

Blue vervain (Verbena hastata) is blooming at Presque Isle State Park where I took this photo on Wednesday. Vervain flowers are so small that the plant looks boring from afar. It is well worth a closer look.

On Thursday Charity Kheshgi and I explored the grassland top of the slag heap at Nine Mile Run. In one area the slag is so porous that rainwater percolates straight though it, creating a desert habitat. Nonetheless we found a vibrant orange butterfly weed (Asclepias tuberosa) in bloom.

Namesake plant: Dwarf St. John’s wort (Hypericum mutilum) is native to North America.

Seeds! Redbud trees (Cercis canadensis) in the city parks have a bumper crop of seed pods this year.

Nodding thistle (Carduus nutans) has gone to seed along the lower Nine Mile Run Trail where it looked like this in June (click here). We saw many American goldfinches feeding on these natural thistle feeders.

Today is our last chance to enjoy July. The weather is lovely in Pittsburgh so get outdoors.

(photos by Kate St. John)

10 July 2021

Pittsburgh’s weather fluctuated this week from pleasant to oppressively humid. Always late to get outdoors, I missed the best part of each day. The flowers were open but the birds were hiding at:

• Duck Hollow and Lower Nine Mile Run on 3 July. 73 degrees, a pleasant day!
• Montour Trail on 5 July. 85 degrees in the shade, cooler in Enlow Tunnel.
• Three Rivers Heritage Trail on the South Side on 6 July. Almost 90 degrees and very sunny.

I was dripping with sweat on 6 July when I found this namesake plant, St. John’s wort (Hypericum prolificum), pushing up from a crack in the sidewalk. What a hardy plant standing tall on a hot day. I wilted after 30 minutes in the sun.

p.s. A story about peppergrass.

(photos by Kate St. John)