Specimen #1: Atrichum altecristatum

Collection #: 1

Scientific Name: Atrichum altecristatum

Phylum: Bryophyta; Bryopsida

Order: Polytrichales

Family: Polytrichaceae

Common Name: wavy starburst moss

Location: South Russell, OH (Willa) Hiram College Field station (me)

Habitat: Lawn area under an oak tree (Willa) Wet soil  right beside the trail (me)

Date of collecting: September somewhere, 2015 (Willa) October 8th, 2015 (me)

Collector: Willa, Cornelia

Notes: Dry leaves usually curl up; sporophytes developing in Willa's sample; sporophytes beautifully developed in my sample with giant, beautiful capsule

How did I key this out:

Fig.1 Group picture                                                                       Fig.2 Single plant

From both the group picture (Fig.1) and the picture of a single plant (Fig.2) above, we could easily tell that this specimen is a plant with the acrocarp growth form. From the leaf picture (Fig.3) we could see that this specimen is with lance-shaped leaves, and the leaves do have a midrib. By knowing these features, we could now go to the key: KEY II: Acrocarps with Lance-shaped Leaves.

Fig.3 Picture of a single leaf

The following steps is how I went through the keys:
1. (B) Plants darker green, yellow green, or brownish black, shoots loosely associated or if densely packed then not in domed mounds; leaves flat or folded but not tubular, with midrib usually visible at least at base of leaf. (See Fig.1 for this fact.) (3)
3. (B) Plants on soil, rocks, trees, or logs in dry areas, or if in wetter areas, not submerged in water; leaves not folded at base. (See Fig.3 and 7 for this fact.) (4)
4. (A) Leaf surface rippled or wavy when wet. (See Fig.3 for this fact.) (5)
5. (A) Leaf midrib conspicuous to leaf tip (extra strips of tissue running along their length, visible as green and white stripes under 20x hand lens). (See Fig.3 for this fact.) (6)
6. (B) Midrib fills ≤¼ width of upper leaf; leaves 0.7-2 mm wide. (See Fig.3 for this fact.) (7)
7. (B) Plants 1-3 cm tall; lower stems often matted with rust-colored fuzz. (See Fig.4 for this fact.) (Atrichum altecristatum, P69)

Fig.4 Plant size

 Fig.5 Cell structure

Fig.6 (a) Immature capsule

Fig.6 (b) Mature capsule

Fig.7 (a) Habitat

Fig.7 (b) Habitat

Description of the species:
Appearance: Plants stand upright and unbranched, 1-3 cm tall and forming loose patches over ground. When wet, leaves spread out and give the plants a star-like appearance from above. When dry, leaves curl in tightly. Stem base is often matted with rust-colored fuzz.
Leaves: Long, narrow swords, 2-8 mm long and 1-2 mm wide. Leaves are rippled and bright green when wet; brown and contorted when dry. Midrib reaches leaf tip and fills no more than a quarter of the width of the upper leaf. Close inspection reveals green and white stripes running along the midrib. Leaf edges are toothed above middle; near tip, margins curve up like sides of a canoe. Tiny teeth are visible along ripples on undersurface of leaf.
Capsules: Cylindrical and usually upright to barely curved, 2-7 mm long, capped by a long beaked lid while developing. Stalk is red, 1-3 cm.
Habitat: Forest floor on mounds, sides of ravines or banks along roads, also in forest clearings and lawns.
Microscopic features: Thin strips of cells, 1-cell wide and 4-6 high in Atrichum altecristatum, compared with 2-4 cells high in A. crispulum, run along the midrib.

Collecting and keying story:

This is the first specimen Willa provided to us during lab for this course. It was a completely dried out sample. We put them under a dissecting scope and dropped water on them, and I was surprised by how fast the leaves absorbed water and stretched themselves. By looking at a leaf closely under a microscope, we figured that these moss leaves only have 1 layer of cells, and then Willa told us that this is actually a fact for almost all the mosses. Moreover, it was kind of easy to key this specimen out as well since all the characteristics for it were pretty clear.

I collected my sample on October 8th, 2015 during the field trip to Hiram College Field station. This class started by the end of August, so in October I already got this trained mental problem of "whenever I see a moss with a sporophyte, I want to collect it". When I saw these plants with those giant beautiful capsules (even with their lid on!), I couldn't help myself. I collected a huge sample with fresh wet soil attached. Later on I figured that it was the same thing as the first one I keyed out, but in the sample Willa provided us there were no developed capsule. So finally I got a good, nice sample with capsule for this specimen.

Phylum, order and family name cited from:
http://plants.usda.gov/core/profile?symbol=ATAL6

Keys cited from:

  Common Mosses of the Northeast and Appalachians by Karl B. McKnight, Joseph R. Rohrer, Kirsten McKnight Ward and Warren J. Perdrizet. This book is in the series of the Princeton Field Guides and was published by Princeton University Press with copyright @ 2013.