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Orthotrichum ohioense

Photo of Orthotrichum ohioense growing on Cephalanthus occidentalis in a marsh area at Salt Fork State Park.
The photo highlights gametophytes with young sporophytes in various stages of development showing calyptra still attached to the sporophytes.
Photo was taken during collection of specimens for preliminary work on a study of the bryophyte flora of Salt Fork State Park, Guernsey County, Ohio in April of 2010.

A link to additional photos of Orthotrichum ohioense

Family: Orthotrichaceae

Genus: Orthotrichum Hedwig, Spec. Musci. 162. 1801 (Lewinsky, 1993).

Nomenclature: Orthotrichum ohioense Sullivant & Lesquereux in C. F. Austin, Musci Appal. 30. n. 169. 1870 [Orthotrichum ohioense Sull. & Lesq.] (Vitt, 2010).

Synonyms: Orthotrichum citrinum Sullivant & Lesquereux; Orthotrichum ohioense var. citrinum (Sullivant & Lesquereux) Lesquereux & James (Vitt, 2010).

Common Name: Ohio Orthotrichum Moss

Gametophyte Morphology: Orthotrichum ohioense is an acrocarpous moss with terminal sporophytes. The plants tend to brownish in color (Crum, 2004). Gametophyte height ranges from 0.4-1.4 cm. (Vitt, 2010). Stems are unbranched and stem leaves are rigid and erect (Crum & Amderson, 1981) to loosely-erect (Vitt, 2010) when dry and erect to spreading when moist (Crum, 2004). The leaves are narrowly lanceolate (Vitt, 2010) to oblong-lanceolate (Crum, 2004) and obtuse to bluntly acute (Vitt, 2010). The margins are strongly revolute to below the apex (Vitt, 2010) and tend to be entire (Crum and Anderson, 1981). The costa is single and ends slightly below the apex of the leaf (Crum, 2004). The upper laminal cells are 8-10 um wide, 1-stratose, with low papillae (Vitt, 2010) and irregularly rounded to transversely oval with evenly thickened walls (Crum, 2004). The basal laminal cells are subquadrate to short-rectangular with rounded corners with no papillae (Vitt, 2010). There are no brood bodies present (Crum & Anderson, 1981).

Sexual condition: Goniautoicous

Sporophyte Morphology: Orthotrichum ohioense has a very short and distinct sporophyte capsule that is generally immersed within the leaves of the gametophyte, as opposed to exserted, which is one way to distinguish this genus from Ulota (Crum, 2004). The seta tends to be less than 1 mm (Vitt, 2010). This tends to make the capsule, which is emergent and urn-like, oblong to ovate, appear sessile (Vitt, 2010). The capsule is 1-1.5 mm long (Vitt 2010) and tends to be pale brown in coloration (Crum, 2004). The capsule has 8 narrow and distant ribs (Vitt, 2010) and is not or only slightly constricted below the mouth when dry and free of spores (Crum & Anderson, 1981). The stomata tend to be immersed (Vitt, 2010) and located in the middle of the capsule (Crum, 2004). This is another way to distinguish the genus from Ulota, which tends to have superficial stomata (Crum, 2004). The peristome is double and the endostome has 8 segments (Vitt, 2010). There are 8 exostome teeth which typically split into 16 small and lanceolate divisions (Crum, 2004). The teeth are reflexed when dry (Crum, 2004) and tend to be finely and densely papillose (Vitt, 2010). The calyptrae are oblong, plicate to mitrate and naked or slightly hairy (Vitt, 2010). Spores 15--21 um (Crum, 2004).

Habitat: On the bark (smooth, rough or hard) of deciduous hardwood trees in mesic forests especially along riparian corridors (Crum, 2004). It is rarely found out in the open. It is normally found at an elevation of 100--1000 meters (Vitt, 2010).

Distribution: The Bryophyte Flora of North America lists Orthotrichum ohioense with a distribution of: N.B., N.S., Ont., Que.; Ala., Ark., Conn., Del., D.C., Fla., Ga., Ill., Ind., Ky., Maine, Md., Mass., Mich., Mo., Miss., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., S.C., Tenn., Vt., Va., W.Va., being wide-spread in the eastern, d eciduous forest zone (Vitt, 2010). In Ohio, O. ohioense is known from 21 counties including Adams, Champaign, Clermont, Clinton, Delaware, Franklin, Greene, Highland, Hocking, Jackson, Lake, Ottawa, Pickaway, Preble, Richland, Ross, Scioto, Vinton, Washington and Wood (Andreas & Snider, 1996). It was collected in Guernsey County in 2010 resulting in a new county record. It has a scattered distribution around the state, with most records occurring in southwest and south central Ohio (Andreas & Snider, 1996).

General Information:

  • Orthotrichaceae is the only family of mosses in order Orthotrichales.
  • There are 120 known species of Orthotrichum (40 in the North American flora) worldwide, with most species being more common in temperate areas (Vitt, 2010).
  • The genus name Orthotrichum is derived from the straight and erect hairs that are found on the calyptra in many of the species (Vitt, 2010).
  • Many species in the family are epiphytic.
  • Orthotrichum ohioense is most closely related to O. stellatum. It can be can be distinguished from O. stellatum by its 16 exostome teeth, 8 rudimentary endostome segments, lightly 8-ribbed ovate capsule, leaves that are lanceolate and bluntly acute at apex, and cells less than 10 um. O. stellatum has 8 paired exostome teeth, 8 well-developed endostome segments, and constricted, strongly 8-ribbed capsules (Vitt, 2010).
  • Orthotrichum ohioense was first collected by Coe F. Austin, a prominent botanist and bryologist from New Jersey. It was attributed in his first major work, the Musci Appalachiani, which was a collection of 450 specimens, raised to 550 by a supplement in 1878, representing above four hundred species. Austin attributed the species to "Ohio and adjacent states" thus justifying the name (Crum & Anderson, 1981).
  • Crum (2004) states "pale capsules with narrow and remote but fairly well-marked ribs, 8 exostome teeth splitting into 16 small, pale divisions, and stomatal chambers surrounded by greatly differentiated cells jutting almost vertically are diagnostic."
  • References:
    Lewinsky, J. 1993. Monographic studies on Orthotrichum (Musci). Bryobrothera, Vol. 2: 1--59.
    Vitt, D. H. 1973. A Revision of the Genus Orthotrichum in North America, North of Mexico. Bryophytorum Bibliotheca, 1: 1--108.
    Crum, H.A. and L.E. Anderson. 1981. Mosses of Eastern North America. Columbia University Press. pp. 714-716.
    Crum, H.A. 2004. Mosses of the Great Lakes Forest, 4th ed., University of Michigan Herbarium. Ann Arbor, Michigan. pp. 311-312.
    Vitt, D. H. 2010. In prep. Orthotrichum. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico. 12+ vols. New York and Oxford. Vol. 28. [See Bryophyte Flora of North America website: Bryophyte Flora of North America, Vol. 2.]
    Andreas, B.K. and J.A. Snider. 1996. A Catalog and Atlas of the Mosses of Ohio. Ohio Biological Survey. Ohio State University Press. Columbus, Ohio.

    Written by Jason S. Larson
    May 2010

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