Tetraphis pellucida
Sp. Musc. Frond., 45, plate 7, fig. 1a–f. 1801,.
Specialized asexual structures usually present. Seta 6–14 mm, erect, straight or ± flexuose, superficial cells smooth and spirally twisted the entire length or spirally twisted and interspersed with sections of prorulate straight cells. Spores 10–13 µm.
Distribution
Throughout Northern Hemisphere
Discussion
Varieties 2 (2 in the flora).
Using growth studies, R. T. T. Forman (1962) suggested that leaf width and shape are influenced by temperature but could be used for species determination in some areas of North America, although it appears to be an inconsistent character and should be used with caution to determine sterile material. The varieties are distinguished by twisting of the superficial cells of the seta in both old, dry, and young, fresh material; the seta itself is twisted when dry.
Selected References
None.
Key
| 1 | Seta smooth, superficial cells spirally twisted throughout entire length | Tetraphis pellucida var. pellucida |
| 1 | Seta usually lightly papillose near base, superficial cells spirally twisted but interspersed with sections of straight cell | Tetraphis pellucida var. trachypoda |