Heterocladium macounii Best

  • Authority

    Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)

  • Family

    Pterigynandraceae

  • Scientific Name

    Heterocladium macounii Best

  • Description

    Species Description - Small plants in dense, rigid, dark- or yellow-green mats. Stems irregularly to rather regularly 1-2-pinnately branched; branches simple, terete to filiform, short, slender, and ascending or more elongate and very slender; stems and branches ± papillose. Stem leaves erect and often secund at tips when dry, erect or erect-spreading when moist, ovate, short-acuminate, somewhat decurrent, 0.35-0.7 mm long; costa variable, single, ending near the leaf middle and often forked or frequently short and double; upper cells irregularly rounded-quadrate and shortly oblong, thick-walled, 1-4-papillose; cells at basal margins subquadrate in numerous rows, those near the costa long-rhombic to oblong-linear. Branch leaves similar but smaller (0.17-0.33 mm long), blunt or acute to short-acuminate, with costa very short and sometimes indistinct, often subsecund at tips. Setae ca. 10-15 mm long; capsules ca. 1-1.2 mm long; operculum rostrate; cilia 1-2. Spores 10-12 pm, smooth. (Not fruiting in Mexico.)

  • Discussion

    Fig. 635

    H. macouniiBest, Bull. Torrey Bot. Club 28: 127.1901.

    The species is represented in Mexico by a slender, often flagellate-branched form, (also common in North America). It is remarkably similar to Cyrto-hypnumpygmaeum (B.S.G.) Buck & Crum in size, appearance, and papillose stems and branches. The virtual absence of paraphyllia as well as a tendency toward irregular branching and costal reduction provide a ready means of distinction from that species. We have followed Lawton (1971) in considering these plants as reduced examples of Heterocladium macounii, although some argument can be made for segregating them as H. heteropteroides var. fdescens Best.

  • Distribution

    On moist, shaded rock at 2100 m and perhaps higher; Hidalgo (above Zacualtipan, Sharp et al. 1827, MICH, TENN) and Puebla (above Santa Rita Ixtapalucan, Sharp 3640, TENN).-Mexico; southeastern United States (in the mountains); southeastern Alaska to Oregon and Idaho.

    United States of America North America| Mexico North America|