Specimen #19: Herzogiella striatella

Collection #: 19

Scientific Name: Herzogiella striatella

Phylum: Bryophyta; Bryopsida

Order: Hypinales

Family: Hypnaceae

Common Name: Tassel Moss

Location: Chagrin Falls Reservation

Habitat: On wood trunk

Date of collecting: September 17th

Collector: Cornelia

Notes: Branches look like little worms or sphagnum

How did I key this out:

Fig.1 Group of the specimen

Fig.2 Tip of the plant under a dissecting scope

Fig.3 Stem leaf structure under a microscope

Fig.4 Branch leaf structure under a microscope

Fig. 5 Cell structure under a microscope

From both the picture of the plant (Fig.1) above, we could easily tell that this specimen is a plant with the pleurocarp growth form. From the leaf picture (Fig.3) we could see that this specimen is with ovate-shaped leaves, and the leaves do not have a midrib. By knowing these features, we could now go to the key: KEY IX: Pleurocarps with ovate leaves without midrib.

The following steps is how I went through the keys:
1. (B)  Branches not flattened; leaves appear to come off all around stem, more or less 3-dimensional. (12)
12. (B) Leaves mostly a single color; capsules either on stalks, or surrounding leaves not white-fringed. (13)
13. (B) Stem green to brown, not particularly contrasting with leaves; mosses of various sizes. (17)
17. (B) Plants of dry to very moist habitats, not submerged or kept constantly wet. (23)
23. (A) Branches appear fuzzy or bristly, wet or dry; leaves wide-spreading nearly at right angle to stem. (24)
24. (B) Plants midsized; leaves 1-2 mm long, tip flat. (25)
25. (B) Stem and branch leaves similar in shape; stem branching irregularly. (Herzogiella striatella, p.305)

Description of the specimen:
Appearance: Forms shiny, bright green or yellowish mats. The horizontally creeping stems divide irregularly into upright branches that are densely packed with leaves. In spite of the crowded leaves, wet shoots seem airy as the leaf tips flare outward up to 90 degrees from erect leaf bases. Dry leaves are drawn in closer, stand upright, and sometimes are slightly pleated; shoots can be gently flattened. 
Leaves: Oval, 1-2 mm long, abruptly tapered to a long narrow tip, cupped. Midrib is lacking. Edges are smooth. 
Capsules: Cylindrical, 1-2 mm long, horizontal, contracted below mouth and pleated when dry, with a short-beaked lid. Stalk is 9-2o mm long and reddish to light brown. 
Habitat: Forest floor, on soil, humus, base of trees, tree roots, rock, and logs in moist shady sites. 
Microscopic features: Upper half of leaf edge is toothed. Compared to other cells in the leaf, cells in basal outside corners of H. striatella are dramatically larger, transparent, and thin-walled. These corners run down onto the stem. Both of these characters are lacking in H. turfacea, whose corner cells are square and not inflated. Stems lack tiny projections beneath leaves. 

Collecting and keying story:

Honestly I don't really remember where did I found this specimen...and keying it out was not easy as well. It is hard to tell whether the leaves are widely spread from the branch or not, and the tip of each individual plant was difficult to observe as well. The conclusion for the keying process was ensured by going though all the possible results and compare them with the actual specimen.

Phylum, order and family name cited from:

http://plants.usda.gov/core/profile?symbol=HEST5

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.