Grimmiaceae. Genus Bucklandiella

1. Upper leaf margins regularly bi(tri-)-stratose in 2-4(-6) cell rows; costae near leaf base 4-stratose 7. Bucklandiella macounii subsp. alpina

Known from a single locality in the Kola Peninsula (Khibiny Mts. ), sporadic in the Caucasus and found recently in Kommander Islands (Russian Aleutians). This species is identified by the unique combination of bi(tri-)stratose leaf margins in multiple cell rows; thick costae; somewhat stiff, glossy plants with weakly branching stems; and very short, hyaline leaf hair-points.

Upper leaf margins unistratose or bistratose in one cell row; costae near leaf base bi-(tri-) stratose 2
2. Basal marginal leaf cells in one row pellucid with more or less thin, not or slightly sinuose walls, forming a hyaline border 3
Basal marginal leaf cells similar to median cells, not forming a hyaline border 6
3. Basal leaf cells with more or less sinuose walls; upper leaf margins uneven; leaf hyaline hair-points reflexed when dry; plants yellowish-green 4. B. laeta

An East Asian species found in Russia in Primorsky Territory, Kamchatka, Kuril and Kommander Islands. Grows on acidic rocks in forest to alpine zones (to 1850 m a. s. l. ). It can be recognized by its leaves that have hair-points straight to reflexed at right angles; hyaline basal marginal borders; sinuose basal cells; and slightly uneven upper margins.

Basal leaf cells with straight, thick, porose walls; upper leaf margins even; leaf hyaline hair-points flexuose when dry; plants olive-, brownish- or rarely yellowish-green 4
4. Multicellular gemmae present in leaf axils 2. B. vulcanicola

A rare East Asian species known from scattered localities in Japan and found twice in Kamchatka. Grows in alpine mountain zone (1070-1220 m a. s. l. in Kamchatka) on exposed, dry, volcanic rocks. It has much in common with B. microcarpa, but differs in having more densely branched stems; hyaline marginal borders with more numerous cells; and, especially by the presence of multicellular, axillary gemmae that only occur in this species of the genus.

Gemmae absent 5
5. Leaves in spiral rows; leaf hyaline hair-points short or lacking, straight, to 0. 4 m long; stems irregularly branched; costae at mid-leaf tristratose; Chukotka 3. B. afoninae

A rare species known from a single locality in Alaska, sporadically distributed in eastern Chukotka and rare in Vrangel Island. Grows on rocky soil in various types of tundra.

Leaves not in spiral rows; leaf hyaline hair-points usually longer, always present, flexuose, 0. 3-1. 1 m long; stems more or less regularly branched; costae at mid-leaf bistratose; widespread 1. B. microcarpa

A widespread species common and abundant in Kola Peninsula, Karelia and lowland European Russia up to Tver Province in places were granite boulders occur. Sporadic in the Urals and mountain areas in Asian Russia from Altai Mts. to the Primorsky Territory, Sakhalin and Kuriles and northward to Kamchatka. Found in southern Taimyr, but unknown in Yakutia. In Chukotka the species is rare; a form with very long hyaline hair-points and intricately branched stems, fo. afoninae Frisvoll, was described from the Chukotka Peninsula. Grows on acidic rocks, rock outcrops and rock fields, as well as rocky soil, in forest to mountain tundra zones. Its diagnostic characters include regularly branched stems with numerous short branches; large area of esinuose, thick-walled, porose cells at leaf base near costae; lower leaf margins with hyaline border of elongate cells; and usually bistratose costae.

6(2). Leaf margins recurved on both sides to near apices or recurved somewhat less on one side; inner perichaetial leaves almost entirely hyaline 7
Leaf margins reflexed on one side 1/2-2/3 leaf length and less recurved on other side; inner perichaetial leaves hyaline only at base 8
7. Costae mostly tristratose at mid-leaf in transverse sections with 3-4 ventral superficial cells 5. B. affinis

A common species in the mountains of Central/Southern Europe and southern Scandinavia, but very rare in European Russia. The species was reported from Karelia, however, no herbarium collections from this area were found. A single record of the species from Siberia (Western Sayan Mts. ) is a misdetermination. Collections from Georgia (Lagodekhi Nature Reserve) at the Russian border indicate it may occur in the mountain areas of Dagestan. It is similar to B. heterosticha in many essential features, but differs in having mainly tristratose (vs. bistratose) costae. It shares this feature with B. sudetica, but the leaves of B. affinis are more widely canaliculate; have margins recurved almost to the apices (vs. in lower 1/2-2/3 on one side and shorter on the other side); and wider, flattened hair-points.

Costae bistratose at mid-leaf, in transverse sections with 3-4 ventral superficial cells 6. B. heterosticha

This species occurs sporadically in NW European Russia and is known from only a single record in the central part European Russia, Tver Province. Grows exclusively on acidic rocks (granites, sandstones) in lowlands and lower mountain zone. It is separated from most other species of the genus by the presence of widely canaliculate leaves with costae 3-4 cells wide at mid-leaf, and longly recurved leaf margins. Its main distinction from B. affinis is the presence of bistratose (vs. tristratose) costae.

8. Alar cells usually enlarged, orange colored; leaf margins unistratose; costae in transverse sections bistratose at mid-leaf, ventral cells with broader lumina than other cells; outer perichaetial leaves reflexed to squarrose when wet 9. B. nitidula

East Asian species recently found in Russia (Kamchatka Peninsula, Southern Kuriles, Zabaikalsky Territory and Buryatia). Grows on rocks in the forest zone (to 500 m a. s. l. ) in Kamchatka, up to the crooked tree forest zone (1250 m a. s. l. ) in Kunashir Island and at 1100-1775 m a. s. l. in Transbaikalia. This species is recognized by its slightly glossy plants and erect leaves with short or absent hair-points and small, but conspicuous group of large, thick-walled, reddish or orange-colored alar cells. It is similar to B. microcarpa in having bistratose costae and elongate upper leaf cells, but differs in having sinuose (esinuose and porose in B. microcarpa) juxtacostal basal cells.

Alar cells not differentiated, basal and alar regions homogeneously colored; leaf margins often bistratose in one cell row; costae in transverse sections (2-)3-stratose at mid-leaf, all cell lumina equally broad; outer perichaetial leaves erect to patent when wet 8. B. sudetica

One of the most widespread and variable species of the genus. In European Russia it grows only in mountain areas in Kola Peninsula and Karelia, the Caucasus and Urals, but is absent in the lowlands. In Asian Russia it is sporadic in the Northern Far East (Chukotka, Kamchatka and Magadan Province), and southward to Kuril Islands, but not found in Primorsky Territory. It occurs also in the mountains of southern Siberia, south of Yakutia, and is known from a few localities in Anabar Plateau (southern Taimyr). Grows on dry or wet acidic rocks from sea level to the lower alpine zone. Distinctive features important for its identificaiton include irregular branched stem; narrowly canaliculate leaves; mainly tristratose costae; short leaf hair-points; short upper leaf cells; sinuose basal juxtacostal cells; and the absence of a marginal border at leaf base.