Pohlia emergens (Müll.Hal.) A.J.Shaw
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Authority
Buck, William R. 1987. Bryostephane Steereana: A Collection of Bryological Papers Presented to William Campbell Steere On The Occasion of His 80th Birthday. Mem. New York Bot. Gard. 45: 1-749.
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Family
Bryaceae
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Scientific Name
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Discussion
Bryum emergens C. Müll., Linnaea 42: 306.1879; Mielichhoferia emergens (C. Müll.) Broth., Nat. Pfl. 1(3): 598. 1904. Type: ARGENTINA. "Argentinia Tucamanensis, in montibus alpinis prope Tafi, Martio," P. G. Lorentz s.n. (lectotype NY!).
The type in NY consists of only a few plants, but they appear to belong to Pohlia subg. Pohlia. The plants are rather dull, very slender, with terminal, paroicous inflorescences and a double peristome. The exostome teeth are pale yellow, slightly bordered, rounded at the apices and reach 250 µm in length. They bear a reticulate omamentation dorsally near the base, and are coarsely papillose in the upper third, a pattem typical of Pohlia but not Schizymenium or Mielichhoferia (Shaw, 1985b & unpubl.). The pale yellow endostome has a cellular formula of 2:4 and consists of a smooth basal membrane to 85 µm high and narrow, slightly keeled but unsplit segments 150-250 µm long (from the capsule mouth). The segments are papillose from their bases upward. Cilia are absent. That the segments occasionally have stout lateral projections might have led Brotherus (1904) to place this species in Mielichhoferia. However, the shape and diflferentiation of the perichaetial bracts, combined with other features, suggest that P. emergens should be excluded from the Mielichhoferioideae.