Polytrichastrum formosum (Hedw.) G.L.Sm.
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Authority
Sharp, Aaron J., et al. 1994. The Moss Flora of Mexico. Part Two: Orthotrichales to Polytrichales. Mem. New York Bot. Gard. 69 (2)
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Family
Polytrichaceae
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Scientific Name
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Description
Species Description - Plants robust, in loose tufts. Stems simple, 5-6 cm tall, densely leafy above, bracteate below. Leaves erect-spreading and tubular when dry, laxly spreading to recurved when moist; sheath oblong, 2 mm long and 2 mm wide, the margin entire, hyaline; h m b narrowly triangular, ending in a short, rough point, toothed at back near the tip, 8-10 mm long, 0.8-1 mm wide; marginal lamina erect, 5 cells wide, serrulatetoothed nearly to the sheath; lamellae entire or finely sermlate in profile, 4-5 cells high, the lamellar marginal cells smooth or finely striate-papillose, in cross-section undifferentiated but somewhat taller than the cells beneath; sheath cells elongate-rectangular, in longitudinal rows, 10(—13) µm wide, 50-60(-80) µm long. Perichaetial leaves with a longer sheath but not strongly differentiated. Setae stout, 5 cm long, 0.5 mm in diameter; capsules inclined to horizontal, pale- or yellowish-brown, oblong-ovate, with 4 acute to rounded angles, 5 mm long, 2.5 mm wide, tapering to the mouth, with numerous superficial stomata in the shallow constriction at base of the capsule; exothecium smooth, without thin spots; exothecial cells moderately thick-walled, quadrate to hexagonal, 35-40 µm in longest dimension; operculum conic-rostrate, with the beak 1/3 to 1/2 the length of the capsule; peristome teeth 64, single, acute, pale-yellow; epiphragm thick, with indentations in the broad edge at the site of attachment ofthe teeth, lacking erect, marginal tooth-like processes. Spores 13-15 µm in longest dimension, finely papillose. Calyptrae hairy, covering the upper portion of the capsule.
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Discussion
Fig. 792
P. formosum (Hedw.) G. L. Smith, Mem. New York Bot. Gard. 21(3): 37. 1971.
Polytrichum formosum Hedw., Sp. Muse. 92. 1801.
Polytrichastrum formosum belongs to sect. Aporotheca, while P. alpinum and P. tenellum belong to sect. Polytrichastrum.
Pogonatum volvatum (C. Müll.) Par. might be confused with Polytrichastrumformosum when sterile, because of stout marginal teeth at limb margins and the profile and cross-sectional aspect of lamellae, but the sheath of the Pogonatum is not hyaline-margined.
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Distribution
Mexico (Ruiz & Pavdn, without locality; "Ste. Madelaine Thai," Hahn).—North America and Eurasia. [Ruiz and Pav6n never collected in Mexico; this may be a Sesse and Mocino collection to which Pavon attached his label.—Editor]
Mexico North America| North America| Europe| Asia|