Bartramia patens Bridel 1803

Bartramia patens

Bartramia patens Brid., Musc. Rec. 2 (3):134, 1803. [Original material: Magellan Straits, coll. Commerson.]

Bartramia diminutiva C. Müll., Bot. Jahrb. 5:79, 1883. [Original material: Kerguelen, coll. Naumann, 1874–1875.]

Bartramia pycnocolea C. Müll. in Neum., Deutsch. Exp. Int. Polarforsch. 2:304, 1890. [Original material: Hochthal über dem oberen Whalerthal, South Georgia, coll. Will, 1882–1883.]

Bartramia subpatens C. Müll. in Neum., Deutsch. Exp. Int. Polarforsch. 2:304, 1890, hom. illeg. [Original material: Whaler Bay, South Georgia, coll. Will, 1882–1883.]

Bartramia oreadella C. Müll. in Neum., Deutsch. Exp. Int. Polarforsch. 2:305, 1890. [Original material: Whalerthal, South Georgia, coll. Will, 1882–1883.]

Plants yellowish green, brownish below, in tufts to 2 cm high. Leaves mostly 4–5 mm long, often becoming detached whole from stem; erect base obovate, ca. 1 mm long, 0.7 mm wide; inner cells usually yellowish, linear, 7–10 μm wide, 75–175 μm long; inner cells of shoulder mostly rectangular, 10 × 25 μm with firm walls; marginal cells to above shoulders very narrow, ca. 5 μm wide, to 75 μm long, thin-walled, hyaline; blade erect to slightly squarrose, lanceolate; margin erect, weakly serrulate to subentire; costa rather obscure, not prominent abaxially, in section with very poorly developed stereid of 20 cells or less; cells of lamina narrowly rectangular, ca. 7 μm wide, 25–40 μm long, papillose; cells near apex less rectangular, generally longer. Synoicous. Perichaetial leaves not particularly elongate. Setae 5–15 mm long. Capsule urn ca. 1.5 mm long, ovoid, inclined, ribbed when dry; exothecial cells mostly 50–60 μm in diameter, some to 75 μm long; peristome double. Spores ellipsoidal, ca. 30 μm long, very minutely papillose or ridged.

The species has been reported from Juan Fernandez by Brotherus (1924) but no material has been seen. The species is known from the Straits of Magellan, Fuegia, South Georgia, the Antarctic Peninsula, and Kerguelen. Both this species and the preceding one are notable for enlarged exothecial cells, but in this species such cells are larger near the mouth of the capsule.