Outside My Window

These beautiful fall crocuses are blooming today near the back entrance of Carnegie Museum and Library.

What a treat to see this vision of spring in September.

(photo by Kate St. John)

As I’ve said before I live in a deciduous place so the ways of conifers are sometimes mysterious.

Take pine sap for instance.   My annual visits to Maine have taught me to check before sitting down under a white pine.  Mainers know that their state flower drips sap (yes, white pine cones are the State Flower of Maine) so they don’t put lawn furniture in the drip zone.  I had some unfortunate experiences with pine sap before I learned this.

Only the female cones cause this problem.  Male cones are small pollen-laden structures that appear in the spring at the base of new growth.  They release huge amounts of pollen, then fall off the tree.

The female cones form on the branch tips and capture the wind borne pollen. It takes two years for them to mature into the familiar woody cone that opens when dry to release the seeds.  Along the way they’re green and drippy.

Why do immature cones drip sap?

That question spawned this post but I haven’t been able to find the answer.

However I have some theories.

• Theory 1:  The cone has to dry out as it matures. Maybe dripping is part of that process.
• Theory 2:  Pine sap has insecticidal properties.  Maybe the oozing sap keeps insects away from the developing seeds.
• Theory 3:  Maybe the sap also keeps squirrels away from the immature cones.

I don’t know why they drip, but the sap certainly keeps me away from them.

p.s.  If you know why pine cones drip sap, please leave a comment and let me know. It’s driving me nuts!

(photo by Steven J. Baskauf from Vanderbilt University Bioimages)

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.)

Ironweed (Vernonia altissima) has been blooming since July.

I never get tired of its purple color.

(photo by Kate St. John)

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.

Sneaky!  Food, shelter and trap.

Read more about this discovery in the PLOS One article.

(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)

In the winter this flowering vine earns the nickname Old Man’s Beard for its hairy, beardlike seeds.

In August it bears white frothy flowers that drape other plants like a Virgin’s Bower.

Clematis virginiana is blooming now in western Pennsylvania.

(photo by Dianne Machesney)

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.

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.

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.

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.

Almost everything about pokeweed is toxic. This makes for confusing instructions about its edibility. The berries and juice can be consumed but the seeds are deadly; the young shoots are OK but the mature plant is not. On the plus side, the deep purple berry juice makes a beautiful red dye.

Pokeweed’s colors are a delight at every stage.

(photos by Kate St. John)

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.

This week I found a bumper crop of haws littering the sidewalks in Schenley Park.

Haws are the fruit of hawthorn trees:  short trees with low branches, tangled twigs and long, thin, leafless thorns (1″-2″ long).  The thorns are a great clue for identifying the tree.  Haw+thorn.

Hawthorn fruits look like small apples or rose hips, all members of the rose family.  They’re a favorite food of robins and cedar waxwings, and people sometimes preserve or ferment them into jam, jelly, snacks and beverages.  The trees occur worldwide in the northern hemisphere so there are many recipes.

Hawthorn trees are really easy to identify as a genus (Crataegus) but difficult as a species because they hybridize and speciate so often.  At one point botanists listed more than 1,100 species in North America but they’ve since clumped them down to about 100.

The Sibley Guide to Trees says hawthorn species are so similar that identifying them is best left to experts.  However, armed with rudimentary knowledge and my Sibley guide, I’ll go out on a limb for these Schenley trees.

My guess is that they’re a variant of Downy Hawthorn (Crataegus mollis) because the haws are ripening in August and the ripe ones soon fall to the ground.

(photo by Kate St. John)

When I visited Jennings Prairie a week ago it took me a while to remember the name of this plant.

The flower spike is interesting but the flowers are unspectacular: small, five-petaled, yellow.

However, the leaves stand out because they’re so odd with small leaflets wedged between larger ones on the stem. 

By examining the leaves I remembered this plant is slightly aggravating.  When it goes to seed the pods have burs that stick to your clothing.

The seeds are “aggravating” and that sounds almost like “agrimony.”

Small flowered agrimony.

I wish I had a mnemonic for the leaves.

(photos by Kate St. John)