Bucklandiella sect. Laevifoliae
in R. Ochyra et al., Cens. Cat. Polish Mosses, 142. 2003,.
Plants moderately sized to large, fairly slender to coarse and rigid, often hoary. Stems 1–12 cm long, creeping, curved-ascending to erect, sparingly or profusely branched. Leaves lanceolate, straight to strongly curved; margins recurved to revolute on both sides to the apex, or less often to 2/3–3/4 of the leaf length, 1-stratose or less often 2-stratose; muticous or piliferous, awns often long, erect, flexuose, flattened, distantly denticulate at the margins and sometimes spinulose on the abaxial side; costa 3–4-stratose and strongly convex abaxially in the proximal portion; alar cells undifferentiated; basal marginal border absent. Inner perichaetial leaves strongly modified, hyaline and epilose, or very seldom shortly piliferous and then chlorophyllose close to the apex. Peristome teeth with a basal membrane.
North America, Europe, Atlantic Islands (Azores, Canary Islands, Iceland, Madeira).
Species 7 (5 in the flora).
The strongly differentiated innermost perichaetial bracts that are ovate, epilose, and hyaline to yellowish hyaline throughout are diagnostic of section Laevifoliae. This is a Euro-American taxon consisting of two species that are endemic to Europe, three endemic to North America, and two that are Euro-American disjuncts.
|1||Leaves epilose, with a chlorophyllose apex, awns absent||> 2|
|1||At least some leaves with a short or long, hyaline to subhyaline awn||> 4|
|2||Leaf margins recurved to 2/3-3/4 of the leaf length; alar cells differentiated, short, thick- walled and porose, forming a well-defined, sometimes auriculate group.||Bucklandiella pacifica|
|2||Leaf margins recurved to revolute to the apex; alar cells not or weakly differentiated||> 3|
|3||Leaf margins 1-stratose, occasionally with 2-stratose patches and smooth in the distal part; costa broader, 80-100 µm, and mostly (3-)4-stratose basally (epilose plants).||Bucklandiella affinis|
|3||Leaf margins usually 2-stratose for 1-3 cell rows, wavy and lumpy in the distal part; costa narrow, 50-80 µm, and usually 3-stratose basally (epilose plants).||Bucklandiella venusta|
|4||Costa broadly canaliculate in mid leaf, moderately convex on the abaxial side and with 4-9 cells on the adaxial side||> 5|
|4||Costa narrowly canaliculate or carinate in mid leaf, strongly convex on the abaxial side and with 3-4 adaxial cells||> 6|
|5||Plants moderately robust and less coarse; leaf margins 1-stratose with infrequent 2-stratose patches and smooth distally; awns weakly flexuose.||Bucklandiella heterosticha|
|5||Plants coarse and robust; leaf margins 2-stratose for 1-3 cell rows and lumpy distally, broadly recurved to revolute throughout; awns stiff, not flexuose.||Bucklandiella obesa|
|6||Leaf margins usually 2-stratose for 1-2(-3) cell rows and lumpy in the distal portion; awns stout, not or weakly flexuose, strongly spinulose||> 7|
|6||Leaf margins usually 1-stratose with occasional 2-stratose spots and not lumpy distally; awns soft, usually flexuose and faintly spinulose||> 8|
|7||Plants robust, almost unbranched; costa broad, 80-120 µm with 4-9 adaxial cells in the basal portion; leaves long, 3-4 mm.||Bucklandiella obesa|
|7||Plants small to medium-sized, copiously branched; costa narrow, 50-80 µm with 3-5 adaxial cells in the basal portion; leaves short, 1.7-2.4 mm.||Bucklandiella venusta|
|8||Costa carinate and predominantly 3-stratose in the middle and lower distal portion.||Bucklandiella affinis|
|8||Costa canaliculate and predominantly 2-stratose in the middle and lower distal portion||Bucklandiella heterosticha|