Just to give you butterfly folks a jolt… I bet you haven’t seen this butterfly on goldenrod in Pennsylvania.
Canada goldenrod (Solidago canadensis) is native to North America but the butterfly is not. It’s a Common Bluebottle (Graphium sarpedon) found in Asia and Australia.
It’s nice to know that goldenrod attracts such beautiful butterflies but how did these two get together?
The photo was taken in Japan. The goldenrod was imported.
Unfortunately Canada goldenrod went wild when it got overseas and is now an invasive species in Asia. It’s such a problem in China that they have eradication programs for it just as we do for Japanese knotweed.
If we could only trade our Japanese knotweed for their goldenrod, we’d all be happy.
(photo by Isaka Yogi on Wikimedia Commons. Click on the image to see the original.)
Continuing on the theme of strange predators here’s interesting news about a plant that preys on insects.
Nepenthes gracilis is a tropical pitcher plant native to Indonesia, Malaysia and Thailand. Like all pitcher plants it eats insects by trapping them in the digestive fluid at the bottom of its tubed-shaped pitcher. The inner surface is slippery when wet to enhance the trapping effect.
This is dangerous for an insect, so why would an ant bother to get near the pitcher opening? Why would it go under the lid?
Nepenthes gracilis tempts insects with a tasty nectar coating on the underside of the lid. In fair weather a skillful bug can perch on the edge, eat the treat, and walk away.
But in the tropics it rains often and heavily. Sometimes insects seek shelter under the lid or are eating underneath it when the rain begins… and then…
Researchers discovered that heavy raindrops prompt the insects’ demise. The lid is poised like a springboard. The weight of a raindrop springs the trap and catapults the insect into the bottom of the pitcher.
(photo from the PLOS One article by Bauer, U., B. Di Giusto, J. Skepper, T.U. Grafe & W. Federle 2012, (CC-BY-SA), Wikimedia Commons. Click on the photo to see the original)
August is prime time for observing pokeweed (Phytolacca americana), a tall perennial that’s easy to find in waste places and along roadsides. Though its name is “weed,” I love its colors.
In winter pokeweed dies back to the taproot but by August it’s 6-10 feet tall with spreading branches. The succulent stems are stout and reddish with deep green alternate leaves up to 16″ long. This plant is big.
Pokeweed’s flowers bloom on racemes that curl up while flowering and droop down when heavy with fruit. This month you can see the flowers and fruits in all stages of development, often on the same raceme.
Here the flowers show five white petal-like sepals and nascent green berries in their centers. Notice how the stem is pink. Pink, white, green.
Pokeweed flowers from bud to incipient fruit (photo by Kate St. John)
After the flowers are pollinated the green berries grow larger. On this stem the berries are all the same age, but that’s pretty rare.
Unripe pokeweed fruits (photo by Kate St. John)
More often the berries range from unripe green to ripe blue-black on the same stem. This raceme shows nearly every stage in the berry life cycle.
Mix of unripe and ripe pokeweed fruits (photo by Kate St. John)
Ripe pokeberries are a favorite food for catbirds and cardinals, robins and mockingbirds, thrashers and waxwings. When the berries are gone the empty stem puts on a final show in gorgeous magenta.
Pokeweed stem after the fruit has been eaten (photo by Kate St. John)
Like many plants pokeweed is toxic though if properly prepared the young shoots can be eaten in Spring. The song about eating pokeweed, Poke Salad Annie by Tony Joe White, might lead you to believe lots of people eat it.
Blooming now in Pennsylvania, the evening primrose fully opens at twilight. Similar species called sundrops are open during the day.
Both flowers are in the Oenothera genus and are masters at opening and closing in response to light. It takes these flowers only a minute to do it. Click here to watch one opening.
Evening primroses are hardy and widespread, in fields and along roadsides. Dianne Machesney found this one at Scotia Barrens.
(photo by Dianne Machesney)
p.s. Monday August 13: It’s cloudy and gray this morning. Evening primroses are open in Schenley Park.
Shrubby St. John’s wort (photo by Dianne Machesney)
28 July 2012
Pictured above is shrubby St John’s wort (Hypericum prolificum), one of the many plants that share my last name.
Most St John’s worts are in the Hypericum genus including common St John’s wort (Hypericum perforatum) which was named “St. John” in Europe because its root was harvested for medicinal and folklore purposes on St. John the Baptist Day, June 24.
“Wort” is an Old English word meaning “root” that appears in the names of many plants including bellwort, bladderwort, golden ragwort, hogwort, toothwort and miterwort. Sometimes it means “plant” instead of root, as in the name of liverwort that was incorrectly thought to cure liver ailments.
As time passed the “St John’s wort” name spread to plants outside the Hypericum genus. In North America, Marsh St Johns wort (Triadenumvirginicum), pictured below, is not a Hypericum and is not even yellow.
Trees provide many birds with food, shelter, and a great place to perch. In southwestern Pennsylvania most of our birds are found in trees. We even have ducks that nest in hollow trees. (Wood ducks)
Trees are good for people too. Did you know …
Trees make the air cleaner by filtering airborne pollutants, absorbing carbon dioxide and producing oxygen.
Just three strategically placed trees can decrease your utility bills by 50%.
Trees reduce noise pollution by absorbing sounds.
Hospital patients who can see a tree outside their windows have almost one full day less recovery time and need fewer painkillers.
Trees around your home can increase its property value by 15% or more.
Sadly many places in cities and suburbs lack trees and miss out on these benefits. In Pennsylvania there’s a statewide program called Treevitalize that works to change that.
Treevitalize helps people plant and maintain trees along neighborhood streets, in business districts, in parks, and along degraded streams. In my area the City of Pittsburgh, Allegheny County, Tree Pittsburgh, the Western Pennsylvania Conservancy, and DCNR joined together to form Treevitalize Pittsburgh and carry out the work here. Their goal is 20,000 new trees!
The fall planting season is fast approaching so now’s the time to prepare. You can learn how to help plant and maintain trees for your own neighborhood at Tree Pittsburgh’s Tree Tender workshops.
There’s a workshop this Saturday, July 28, 9:00am to 4:00pm at the Millvale Community Center, 416 Lincoln Avenue in Millvale.
Or attend the next one on Saturday September 15, 9:00am to 4:00pm at the Western Pennsylvania Conservancy’s offices, 800 Waterfront Drive on Washington’s Landing.
