Robertr. Ireland Jr.

Isopterygium Mitten subg. Dolichotheca Lindberg; Sharpiella Z. Iwatsuki

Plants medium-sized, in thin to dense mats, light to yellowish or dark green, somewhat glossy to glossy. Stems creeping to ascending or erect, simple or sparingly and irregularly branched; hyalodermis present, sometimes indistinct, central strand usually indistinct or absent; pseudoparaphyllia absent (foliose in H. adscendens). Stem and branch leaves similar, spreading to squarrose, , ovate or lanceolate, not or weakly plicate; base decurrent or not; margins plane, serrulate to serrate (serrulate to entire in H. adscendens); apex acuminate to long-acuminate; costa double and short or rarely ecostate; alar cells usually clearly differentiated, few quadrate, rectangular, or abruptly inflated, rounded cells present; laminal cells smooth. Specialized asexual reproduction absent. Sexual condition autoicous or dioicous; perichaetial leaves ovate-lanceolate, apex gradually acuminate, acumen occasionally filiform. Seta light brown to red or yellowish. Capsule erect to inclined, oblong or cylindric, straight to arcuate, often contracted below mouth when dry; annulus 2- or 3-seriate, deciduous, cells large; operculum conic to conic-apiculate; peristome double; exostome teeth with external surface cross striolate proximally, papillose distally; endostome basal membrane high, segments narrow, keeled, cilia 1-3, approximately same length as segments, sometimes absent. Calyptra naked. Spores spheric to ovoid, minutely papillose.

Species 7 (4 in the flora): North America, Mexico, Central America, South America, Europe, Asia, Africa; terrestrial habitats at low to high elevations predominately in temperate and boreal regions.

Stems of Herzogiella often have large, thin-walled epidermal cells and smaller, thick-walled, cortical cells in few rows. The axillary hairs have two basal cells and two apical cells; the sparse, papillose rhizoids emerge in the leaf axils or just below, or are often restricted to stem bases. The leaves are rigid, symmetric, concave, and sometimes distally secund at the stem and branch apices; there are sometimes one to four alar cells along the margins that are differentiated from the thick-walled, linear-fusiform laminal cells. The inflorescences are near the base of stems; the seta is often twisted; the capsule is usually striate when dry, with a wrinkled neck; the exostome teeth are bordered and internally trabeculate; and the endostome is papillose.

SELECTED REFERENCES Ireland, R. R. 1990. Scanning electron microscopy of spores of Herzogiella. Lindbergia 16: 169-179. Ireland, R. R. 1991b. Synopsis of the genus Herzogiella for North America. Lindbergia 17: 111-115.

Lower Taxa

• Herzogiella adscendens (Lindberg) Z. Iwatsuki & W. B. Schofield
• Herzogiella seligeri (Bridel) Z. Iwatsuki
• Herzogiella striatella (Bridel) Z. Iwatsuki
• Herzogiella turfacea (Lindberg) Z. Iwatsuki