Thursday, March 4, 2010

Wrong and Wrong Again!

Let me tell you of two important errors I have cleared up in the course of the last seven days.

ERROR ONE: Regarding Lichen

Until earlier this week I thought lichen was a plant. I had once heard it was a food of reindeer in Lapland. I knew it came in various forms, and that one sort grew in gray-green patches on the bark of the Callery Pear trees lining my street. I had also noticed that it was a prominent feature on the branches as well as on the trunks of those trees that were a bit thinner.

These trees are no match for the winds known to howl down this side street. Planted to replace large maples lost to the installation of the storm sewers in the 70s, these trees grew quickly but are not hardy. Many have lost some very large limbs. But they do look beautiful for a week or two in April when they are a mass of snowy blooms.

I had never really considered the situation, but if I had been forced to make a guess, mine would have been that lichens on tree trunks were making these weak trees weaker.

I was wrong on so many levels! First off, lichens are not plants. They represent, rather, a symbiotic association between a photosynthetic organism (most commonly a green algae) and a fungus (often an ascomycete, or sac fungus). Neither of these organisms is currently considered a plant (although these things have been known to change).

The cells of the photosynthetic organism are held in place by a vast, densely branched network of fungal hyphae (filamentous strands). Each organism makes a contribution to the partnership. The photosynthetic partner provides nutrients to the fungus; the fungal hyphae provides an environment in which the photosynthetic partner can anchor.

Do lichens damage the trees on which they grow? The answer seems to be “no.” The hyphae do not actually penetrate the cells of the host tree. The lichen is only parking on the tree, not harming it.

Lichens do not grow in shade. When a tree on which lichen is growing loses limbs to disease or a storm, more light becomes available, and the lichen proliferates. Thus a tree covered with lichen may be a sign that the tree is in decline, but the lichen is not the reason why.

The absence of lichen is a larger cause for concern. Lichens absorb heavy metals and sulfur dioxide in the atmosphere. When its system becomes overloaded with accumulated toxins, the lichen dies. Lichens are thus good indicators of air pollution. Anti-sulfur dioxide legislation in the last 25 years is allowing lichens to return to formerly polluted areas. 

Their gray-green presence should actually be a welcome sight. Be wary if the lichen around you disappears.

ERROR TWO: Regarding Parmesan Cheese

A Parmesan cheese rind is a culinary treasure, not a discard.
Ever since I first convinced myself I could afford it, I have splurged on imported Parmesan, the kind that comes from the gourmet cheese section in wedges with a rind and a very high price tag.

I have always cut the rind off as close to the cheese as possible, complained about how the rind was included in the price, and promptly thrown the rind away.

Those days are over. At the end of December I read a recipe in the New York Times for Proven├žal Tomato and Bean Gratin that sounded simply great. And one of the ingredients was a Parmesan cheese rind! I tried to get over my past wastefulness and added Parmesan cheese to the grocery list.

Last weekend I made the recipe (over several days, this is really slow food). The rind went into the bouquet garni. Such a fragrant aroma filled the house as the beans simmered, a smell that kept me in a constant state of hungry! When I finally fished it out, the rind was a gummy, gooey mess, dripping with melted cheese. I couldn’t resist chewing off the last soft remnants. Bliss. When baked off the next day, the bean dish turned out to be one of the finest things I have ever made, well worth all the time and dirty dishes.

I am so late to this party. Googling shows that such rinds have many uses in Italian culture culinary and otherwise, including the feeding of softened rinds to toothless infants. The rinds can also be added to soup and risotto and frozen until needed, but no one ever told me.  

Better late than never, I vow never to toss another rind. 

1 comment:

  1. Good to know on both counts.

    Feed the fish.