Wednesday, July 30, 2014

Nigh Noon on Nippenicket



Loaded up Musketaquid (skin-on-frame kayak) and Guppy (possible name of tiny new plastic kayak) for a couple of hours on favorite nearby pond.  First time paddling in weeks.  Left shore elevenish.  No agenda.  I said, "I'll follow you."  Son said, "no, I'll follow you."  So we followed each other vaguely in the direction of the far end of the mile-long pond, making discoveries as we went.  


Red-winged blackbird repeating unfamiliar call 
that kept me guessinguntil I got a clear look at him.

Nippenicket's shoals and islands make it more interesting.

 A tiny "cove" has white waterlily (Nymphaea odorata) and pickerelweed (Pontederia cordata)
in the foreground, while royal fern (Osmunda regalis center left) peeks from the shadows ashore.


Stephen among the water shield (Brassenia shreberi),
easily identified by shield-shaped leaves with leaf stems in the center.


  Scattered white flowers at the surface announce the flowering of the underwater plant fanwort
(Cabomba caroliniana) with its finely-divided, dichotomously branching leaves.


Herbivores busy everywhere, but the white water lily leaves first got my attention by the uniformity of the holes, then focused it when I saw that the holes were being cut out as if with scissors!  No idea by what.


 Perfect weather: enough cloud to make sky interesting, 
enough wind to keep us cool without making paddling difficult.


The whole northern end of the pond is choked with water milfoil (Myriophyllum)--another alien invasive--and we passed up a closer look at a marsh to get ourselves disentangled.  

Ashore later at the Harry C. Darling Wildlife Management Area, we stretched our legs and poked around.

 Musketaquid ably bears my weight in its 12 foot length,
while 8-foot Guppy rides high with Stephen.


Pickerelweed up close.  (I tried without success to catch a visiting bumblebee in the photo.)

Alder (Alnus), with its double-toothed leaves and fruit ("cones");
below are last year's cones, long ago opened but still hanging around.


Sweetpepperbush (Clethra alnifolia)--a very common shrub of wet places--in flower.
The toothed leaves are wider toward the tips.  The dried fruit will look a bit like peppercorns. 

On the way back to the launch area, we stopped at a little islet we'd never been to. 

 View looking westward.
Purple loosestrife, an alien invasive.

Looking south toward the launch ramp a quarter-mile away.

We raced informally back to the launch.  Stephen's smaller boat's lower wetted surface (friction) and lighter weight was trumped by my boat's longer waterline (higher top speed) and stronger arms.  --not to mention that winning meant more to me (an official Old Guy) than him.  So I beat him handily.  We were back on the road before 2pm.

Friday, July 25, 2014

Eastern Hemlocks and the Threat of Woolly Adelgid

Full-grown.

Undersides of flat needles are striped.



Spring growth.

Young cones.

Mature cones.

From the spindly trees folks grow around here, and the way they crowd them and torture them into HEDGES, for all love, you'd never know that the eastern hemlock(Tsuga canadensis) is a majestic member of late-stage successional forest here in New England. 

I have been collecting locations of eastern hemlocks (Tsuga canadensis) on my neighborhood perambulations over the last month or so, and have a nice list of trees I look at regularly.  I was moved to do this less because of its iconic status--the third most prevalent tree in Vermont--than because of the danger eastern hemlock faces.  This tree is endangered by yet another of our many alien invasives: the woolly adelgid.  


Our local trees range from sad and tortured to moderately majestic.
 
 


Woolly adelgid (Adelges tsugae) was imported accidentally from Japan, and was first noticed in the US near Richmond, VA in the 1920s.  It is now affecting eastern hemlocks as far north as Massachusetts.  Woolly adelgid is an aphid-like "true bug" (insect order Hemiptera) that sucks the sap and starch from hemlock twigs, reducing their food stores.  This weakens the tree, allowing other insect, disease and drought stresses to overwhelm it.   

Wooly adelgid spreads short distances mainly by wind, and by birds and other animals the sticky egg sacks cling to.  Transport of infected nursery trees can spread the insects more widely.  



Each cottony mass tyically hides an individual and its several hundred eggs.

You will know you have this on your hemlock tree if you see the cottony egg masses on the undersides of twigs.  Affected trees will gradually lose needles, becoming more "transparent" and turning grayish.  Trees here in the north typically die four to ten years after infestation.  If allowed to expand unchecked, the woolly adelgid could doom so many of these beautiful trees that whole forest ecosystems could be irrevocably altered. 


Property owners can spray their smaller infested trees yearly with a non-toxic insecticidal soap or horticultural oil; these smother the insects.  Tree foliage insecticides will keep on killing for several years, but are more toxic.  Trees too large to spray can be treated with soil drenches or other chemicals that are absorbed and transported throughout the tree, but are not safe applied near bodies of water.  For whole forests, several insect species that feed exclusively on wooly adelgid were deployed beginning in 2002 in hopes of bringing the pest population down to manageable levels over the long term.  

A nice video pulls all this (and more) together here.
  
My own little darling at about ten years old is almost chest-high, and free of adelgid.
There are a dozen or so stands of eastern hemlock around my neighborhood, many consisting of several trees.  (Probably thirty or more trees of all sizes could be counted if including individuals in hedges.)  Of these, three stands have obvious signs of woolly adelgid.  There may well be more--I cannot closely examine trees in other people's yards.  My own was a tiny individual transplanted to the woods behind our house; ten or so years later it is only waist-high, but free of insects.  If landowners keep an eye on their own trees and treat them if needed, I have hopes that the spread of the insect can be slowed--at least locally. 

What can you do?  If you have any hemlocks, watch them.  If you find woolly adelgid, consult with state agencies on what treatment would be best.  If you see the insect on your neighbor's tree, let them know.  Don't move an infected tree to a new location.

Tuesday, July 22, 2014

Take the time to watch a flower become a fruit

It's well worth it.  It will cement in your consciousness the connection between flower and fruit.  And since every flowering plant is a little different, you learn a little more with each one you watch.


Flowers have a great variety of forms, but we have to start somewhere!
Image: Amer. Museum of Natural History 
(http://www.amnh.org/learn/biodiversity_counts/ident_help/Parts_Plants/parts_of_flower.htm) 









The fruit--a closed container around the seeds--is what sets flowering plants apart from other plant groups such as conifers, ferns, etc.  The fruit develops from the ovary (containg ovules that will become seeds) at the base of the pistil (female part) of the flower.  Along the way, most other flower parts, such as stamens (male) and petals fall off.  (Some parts may remain: the five little triangles at the end of an apple are the sepals that originally covered the apple flower bud.)

Fruits come in tremendous variety.

The "seeds" (really fruits) of grasses in many cases look much like the flowers, such as the deertongue grass (Panicum clandestinum) in my "prairie garden."


The shape of other fruits can be hard to predict from the flower.  Here is the red maple (Acer rubrum) I watched in the spring.  The first photo is male flowers, the rest are female flowers/fruits of increasing age.
 
 
 
 
 


Often you can see several stages at the same time, in flowers of different ages on the same or neighboring plants. 


Here is common milkweed (Asclepias syriaca) in my "prairie garden."

Plainly only a few flowers in each cluster produce pods; the rest die or their pods are aborted.
In the fall each pod will mature and split open to release hundreds of flat seeds, 
each floating on the wind below a spray of silken fibers.



Sometimes you can see a gradual process so that the end result is predictable.  Pokeweed* is an annual weed that produces dark, juicy berries that begin as tiny, berry-shaped ovaries.  (In flowering plants, the ovary is the base of the pistil--i.e. female flower part--and contains the ovules that will become seeds.  I think botanists borrowed the term by analogy from animal anatomy.)

The ovary shows at the center of the open flower.  It looks like a miniature berry.


Some flowers can be hard to "catch in the act" of becoming fruits, such as dandelion and Queen-Ann's-Lace, which close up and transforms "in secret."
Dandelion (Taraxicum officinale) flower at left, closed at right, open once more with mature fruit in center.
Image from http://www.washingtonpost.com/wp-srv/special/metro/urban-jungle/pages/110419.html


The flower cluster of Queen Ann's Lace or Wild Carrot (Daucus carota) closes to form
 a "bird's nest," before making the bristly little fruits you can just make out in bottom photo.


Look at a few kinds of flowers in your neighborhood.  Visit them every few days and watch them change!


*Pokeweed, Phytolacca americana, is the only plant I know that is sometimes listed as poisonous, yet appears in old cookbook recipes for "pokeberry pie."