10. Bucklandiella macounii (Kindberg) Bednarek-Ochyra & Ochyra in R. Ochyra et al., Cens. Cat. Polish Mosses. 146. 2003.
Racomitrium macounii Kindberg, Bull. Torrey Bot. Club 16: 93. 1889; R. heterostichum var. macounii (Kindberg) G. N. Jones; R. robustifolium Kindberg
Plants medium-sized to moder-ately robust, rigid, in dense or loose tufts or patches, reddish green, reddish brown, brown or olivaceous at the apices, reddish brown to blackish proximally. Stems 3.5-6(-13) cm, ascending to erect or prostrate, simple or sparsely branched. Leaves erect-appressed, straight to distinctly contorted when dry, erect-patent to spreading when moist, narrowly lanceolate, (1.5-)2.2-3(-3.2) × (0.3-)0.5-0.8 mm; margins broadly or narrowly recurved to 1/2-2/3 of the leaf length on one side, plane or faintly recurved in the broadest part of the leaf on the other side, strongly thickened and bulging, 2(-4)-stratose in (1-)2-3(-6) cell rows distally, 2-stratose in 1-3(-4) cell rows in the median and upper basal parts and 1-stratose close the base; apices gradually tapering at an attenuate point, muticous or piliferous, awns short, to 0.2 mm, terete, reddish or yellowish hyaline, erect to recurved when dry, strongly spinulose, not decurrent; costa percurrent, robust, strongly convex abaxially and rounded to elliptical in outline, 60-100(-150) µm wide basally, 40-70 µm wide near the apex, (3-)4(-5)-stratose with 3-6 larger adaxial cells in the basal part, 3-4-stratose with 3-5(-6) adaxial cells in the middle and (2-)3-4-stratose with 2-4 adaxial cells in the distal part; laminal cells 1-stratose with 2-stratose streaks, smooth or moderately papillose; basal laminal cells rectangular, 25-55 × 8-9 µm, with sinuose-nodulose, thick walls; alar cells undifferentiated; basal marginal cells absent or more or less distinct, composed of 15-40 short, transparent, not or moderately sinuose cells; medial and distal laminal cells irregularly isodiametric to short-rectangular or oblate near the margins, 5-25 × 8-9 µm. Inner perichaetial leaves ovate-lanceolate, without or with a very short hair-point, not or weakly differentiated. Seta brown, 4-7 mm. Capsule brown, slightly glistening, obloid-cylindric, 1-1.9 × 0.5-0.8 mm; operculum stout, convex-conical to shortly rostrate; peristome teeth lanceolate, 330-450 µm, reddish or orange-brown, densely spiculate papillose, variously split into 1-3 prongs, perforated or undivided, arising from a fairly short basal membrane, 35-50 µm high. Spores 12-14 µm.
Subspecies 2 (2 in the flora): North America, Eurasia.
Bucklandiella macounii is a prominent species that is diagnosed by its regularly 2-stratose or sometimes in places 3-4-stratose leaf margins in 2-4 or even as many as six cell rows forming bulging thickenings, very short, to 0.2 mm, stout, terete, strongly spinulose and recurved, subhyaline or hyaline awns, as well as very strong costae that are strongly convex, rounded to elliptical in outline on the abaxial side, 4-stratose in the basal and median parts, and plants typically reddish tinged. The species is most similar to the highly variable B. sudetica, especially to plants designated as forma kindbergii; the differences between these taxa are discussed under 12. B. sudetica.
