Tuesday, March 8, 2011

A Fruit Salad of Mosses (apples and pears, that is)

In early spring botanists get itchy feet and head out to find the first blooms of the season. Unfortunately, they are initially met with standard fare such as Erigenia bulbosa, Lamium amplexicaule or Houstonia minima. If you find yourself in this situation and since you are peering intently at the ground anyway, you may as well keep a humble eye out for a bryophyte or two; no doubt you will see many.

Here are two of the more easily identified mosses you could encounter. Though not a purely unique character, both species have rather spherical capsules. The first is Physcomitrium pyriforme.
In my experience, this moss is usually found in rather disturbed or recently burned areas with full sun and is readily identified by the tongue-like leaves with apiculate tips and the pear-shaped (broadly obovate) capsules; a character from which the species epithet is derived (Pyrus being the genus of pears). The second species is Bartramia pomiforme.
This is a species of higher floristic quality. It is an acidophile and is pretty much restricted to wet sandstone ledges, bluffs and terraces in shaded forests; the kind of places you expect to see an abundance of mosses. With its narrow pointed leaves, yellow-green coloration and soft texture there are few mosses with which to confuse it. The nearly perfect spheres that are the capsules pretty much seal the deal. Though I don't like to perpetuate the use of common names, this one is apt. It is called Apple Moss which jives well with the specific epithet (a pome being the fruit type of the apple). At maturity the capsules turn reddish-brown and then look so much like apples that Eve herself would not be able to resist them.

And if you have no taste for mosses, fruity or otherwise, it won't be long before the woods are once again heavy with tracheophyte greenery and the floral distractions there unto.

7 comments:

M.Whittemore said...

I sure won't forget these identification characteristics. I'm glad somebody has the courage to pot about mosses. They are so fascinating yet it's tough to find a good field guide. Do you have any suggestions?

Sara Rall said...

How cool! I've always been intimidated by mosses (and would love to hear of a field guide).

In early spring flowers you didn't mention the first one around here (NJ), the aptly named Draba verna.

Justin Thomas said...

Ha! I almost included Draba verna in the short list, but excluded it for brevity.

I have never heard of or seen a useful field guide to mosses. With the plethora of natural history field guides published in the last several years, I'm surprised there hasn't been one. There are published keys, but they really stress cellular characters. Most every professional bryologist I have talked to has told me that this is the only way to identify them, but as I gain experience with them as a field botanist, I'm not convinced that they can't be identified based on macro characters and habitat.

The closest thing to a field guide I have seen is "A Trailside Guide to Mosses and Liverworts of the Cherokee National Forest" by Paul Davison. It has great photos and descriptions of many common moss and liverwort genera of the eastern U.S. It can be found on Blurb.com for $33. It is definitely a good starting reference and great eye candy.

M.Whittemore said...

Wow, your're right! Great reference! Thanks for sharing. Here is the URL for anybody else interested.

http://www.blurb.com/books/422248

It allows you to look inside the text. Awesome, I'm going to get this!

lfelliott said...

How about "Walk Softly Upon the Earth: A Pictorial Field Guide to Missouri Mosses, Liverworts and Lichens"? As with guides of this type, one is left wondering if the organism you are observing is not covered. A complete key (based, as you say, on field characters) would be nice. At least don't make me use a compound microscope! Thanks, Justin, and keep the mosses coming!

Justin Thomas said...

The "Walk Softly" book has several horrible mistakes in it (moss photos in the liverwort section, etc) and is barely bordering on useful. However, I do admit it was my first moss book and I learned a lot from it.

Virginia said...

Perfect timing. I just read the blog a few days ago and today in digging up my garden I saw this moss and said, "Hey that's the Physcomitrium from Justin's post! Very exciting! It's really tiny, like 1 cm tall, yes? Very cute. Thanks!