Thelia is a small genus of moss containing only three species, T. hirtella, T. asprella, and T. lescurii. This genus is restricted to the United States. There is some conflict currently as to whether Thelia falls into the family Leskeaceae or Thuidiaceae. Current references were found to have different opinions on this subject.

General Characteristics

· Variable color. Plants can be green, yellow-green, yellow-brown, grayish, or bluish.

· Usually found growing in sparse to dense mats of pinnate or irregularly branched, creeping stems.

· Stems usually covered with rhizoids (radiculose)

· Leaves usually crowded and overlapping (julaceous/ imbricate), and having a raggedy, fringed appearance (ciliate) with deep, irregular divisions (laciniate).

· Leaf shape slightly rounded triangular with the base broader than the apex (deltoid-ovate)

· Leaves having a single costa (midrib), which is usually thin and ends at or just above the middle of the leaf.

· Leaf cells are firm walled, diamond shaped (rhombic), and papillose (roughened by small protrusions)

· All members are pleurocarpus, (producing sporophytes laterally rather than at the tip).

· All members are phyllodioecious, the male plants being extremely small and resting on the leaves or rhizoids of the female plants.

· Sporophytes are infrequently produced.

Individual Species Characteristics

Thelia hirtella

Habitat: On the bark of trees and shrubs, occasionally on rocks, logs, and stumps. Usually found in shaded forest areas.

Appearance: Plants green to brownish-green; leaves broadly ovate.

Distribution: Throughout Eastern North America including coastal areas.

Minimal evidence has been found linking this species with Carolina Wren nest construction. In one such case, a nest was discovered in which 83% of the material used for construction was T. hirtella. In the forest in which the nest was found this species is not common or even easily located. This seemed to indicate that the wrens had selectively searched for T.hirtella in order to use it in the nest construction (Reese, 1984).

Thelia asprella

Habitat: On the base of deciduous trees or stumps, occasionally on rocks in shaded forest areas.

Appearance: Plants gray-green; leaves more slender than those of T. hirtella.

Distribution: Throughout Eastern North America, but less so than T. hirtella and excluding coastal areas.

This species was used in studies to evaluate the Critical Point drying technique which can be used for specimen preparation before electron microscopy (Magill, et. al., 1974).

Thelia lescurii

Habitat: Dry, sandy soil , occasionally rocks and tree bases. In dry, open sites.

Appearance: Gray-brown and similar in appearance to T. asprella.

Distribution: Sparsely distributed throughout Eastern North America.

References

Crum, Howard.1983. Mosses of the Great Lakes Forest. University of Michigan. Ann Arbor.

Magill, et.al. 1974. Evaluation of the Critical Point Drying Technique and its Applications in Systematic Studies of Mosses. Bryologist. 77:628-631.

Reese, W.D. 1984. Manual of Mosses of the Gulf South.

Written by Jennifer Gray