Witch’s Broom

A lot of the coniferous trees in this area have these strange tangled clumps in their branches. They look a little like squirrels’ nests or even, from a distance, porcupines. I’ve been wondering what they are – some odd plant parasite, perhaps? – and I finally found my answer: witch’s broom.

From Wikipedia: “A witch’s broom is a disease or deformity in a woody plant, typically a tree, where the natural structure of the plant is changed. A dense mass of shoots grows from a single point, with the resulting structure resembling a broom or a bird’s nest.” Apparently of diseases, pests, and parasites can cause trees to form them. And they do get used as nests on occasion, by flying squirrels, among other critters.

Have you seen any witch’s broom in your area?

The Mountain Pine Beetle

As you drive through Rocky Mountain National Park you see a lot of mountainsides (started to type hillsides and corrected myself!) that look like this.

I admit to increasing the color saturation on this photo slightly to bring out what I want you to see, but the large swaths of red-brown trees are obvious regardless. Something is attacking and killing large numbers of lodgepole pines. The culprit is the mountain pine beetle, Dendroctonus ponderosae.

The dead and dying trees are everywhere you turn.

Pine beetles are native to North America, but droughts and warm winters (likely due to global warming) have led to an unprecedented explosion in their numbers. They infest a pine tree by laying their eggs under its bark, which introduces a fungus into the tree that blocks water and nutrient transport as well as the flow of the sticky pitch, with which the tree might otherwise defend itself. (This is actually similar to how the invasive ambrosia beetle, which I’ve written about previously, attacks bay trees.) Apparently this leads to characteristic blobs of pitch forming on the surface of the bark, and if I’d known that I’m sure I could have found examples to photograph but I didn’t know what I was looking for while I was there.

One of the more effective management techniques is to remove affected trees before the beetles can spread, and we saw some places in the national park where tree removal had been taking place.

Unless something changes, this epidemic could continue indefinitely. Very sad.

Elegy for the Red Bay

Dutch elm disease.  Chestnut blight.  Hemlock woolly adelgid.  Emerald ash borer.  It’s the same old story over and over again, and we all know how it goes.

Red bay, Persea borbonia, is a common tree here on the island.  It’s in the laurel family, and yes, it’s related to the bay from which we get bay leaves for cooking; its leaves have a wonderful aroma when crushed.

Most of our red bays, though, are currently sporting as many branches of brown leaves as of green.  Is it because it’s winter?

Peer up into the canopy.  Brown, brown everywhere you look.  Why?

The redbay ambrosia beetle, Xyleborus glabratus, is native to Asia.  In 2002 it was discovered in Savannah, Georgia, and it has been spreading south since.  The beetle brought with it a fungus with which it lives in symbiosis.  The beetle tunnels into a tree in the laurel family, and inside the tunnel it cultivates the fungus, which is its only source of nutrition.  The fungus consumes the tree’s xylem, and the beetle, in turn, consumes the fungus.

And our red bay trees die before our eyes.  The disease is moving south toward Florida, where it will cut the crop of another member of the laurel family, the avocado, in half.

The American elm.  The American chestnut.  The eastern hemlock.  A long list of ash species.  And now, the red bay.

Mayapple Polka-Dots

In particularly wet, shady areas of the forest, some of our mayapples have been developing a case of yellow spots.

Is it a disease?  A sign of stress, from getting too much water or not enough sunlight?  After doing some digging online, it looks like this may be a mild case of a fungus called mayapple rust.  Here’s the spots as seen from beneath.

In other news, check out what the jack-in-the-pulpits look like now that they’re done blooming!

Freaks of Nature

I love how spring happens in tiny increments.  This week the snakes suddenly woke up and were everywhere; no one had seen a single one until Tuesday, when suddenly every trail group was coming back talking excitedly about garter snakes and water snakes and black rat snakes.  Hooray herps!  Yesterday morning I heard the first towhee song of the season (drink your teeeeeaaaaaaa!).  And of course, the wildflower bonanza is ongoing – the spring beauties and yellow violets are going nuts at the minute, and the jack-in-the-pulpits and wild ginger and white violets and phlox are getting started… I could go on, but I feel like I need to post something other than just lists and photos of the wildflowers blooming here, as much as I love them.

There’s a whole southern part to this property that I really have yet to explore at all, so this afternoon I decided to hike to the covered bridge and back, somewhere I hadn’t been yet.  There were a lot of sessile trilliums (Trillium sessile, a.k.a. toadshade, a wonderful name) along the trail, which don’t have the big white open flower you probably picture when you think of trillium, but they still have that whorl of three leaves.  Here’s a normal sessile trillium.

See?  Three leaves, three sepals, three curled-up reddish brown petals.  That’s where the “tri” in trillium comes from, after all.  But a little farther down the trail I found this bizarre creature:

Four of everything!  Is a four-leaf trillium more or less lucky than a four-leaf clover?

There were also lots of these long-stemmed leaves around.  Can you guess what they are?

They’re hepatica!  Normal hepatica leaves hug the ground pretty closely, but the plant can get infected by a rust that causes them not to flower and instead shoot up these tall, thin leaves.  Then flies land on them and “mix the gametes around,” to borrow some technical terminology (ha ha) from a botanist I know.  Don’t worry, though; as far as I know this rust is a native disease, as normal and natural as the flowers themselves, not something exotic that’s going to wipe out all the hepatica in North America.

Eventually, following my trail map, I arrived at a perfectly normal, modern bridge where a local road crossed the creek.  Not a picturesque old covered bridge.  Had I been tricked somehow?  Eventually I realized that I just had to cross that bridge and pick up the trail on the other side, and the actual covered bridge was just a bit farther down.  It was lovely (despite the graffiti), an old, barn-red structure flanked by enormous gnarled sycamore and osage orange trees.

Anyway, I completed my Red Cross certification in Wilderness and Remote First Aid yesterday and now hypothetically know what to do in the event of a sucking chest wound in the middle of nowhere, which makes me feel very competent and outdoorsy.  Hope everyone else’s weekend was as productive and gorgeous as mine!