1.Upper
leaf margins with large teeth; capsules emergent 1. T. angustatus
In most territory of Russia
this species as widespread as T. mnioides, and they often
occur in one tuft. In recent decades it was found in boreal forest
of the Middle European Russia, in more southern areas, putatively
expanding southwords, and simultaneously it was discovered in the
Caucasus for the first time. Serrate margin is sufficient to
recognize sterile plants.
— Upper leaf margins
entire; capsules long-exserted 2
2.Capsules
cleistocarpous, pale 5. T. paradoxus
Tetraplodon paradoxusis mainly an Arctic species that occurs on the Arctic Ocean islands,
in continental Arctic regions and southwards into the open northern
taiga of permafrost areas (e.g., along the Verkhoyansky Mt. System in Yakutia). It was also collected by L.V. Bardunov in the
Khemchik Mt. Range of southern Krasnoyarsk Territory near the border
with Tyva Republic. This species occurs in the northern areas of
North America (Alaska, northern Canada, Greenland); in Europe
outside Russia it is known only from the northern parts of
Scandinavia and on Svalbard. Tetraplodon paradoxus grows on
reindeer dung. Although it sometimes apears to grows directly on
soil in the tundra, probably the soil has been fertilized by dung.
— Capsules stegocarpous,
intensively colored (rarely pale) 3
3.Plants
in very dense tufts; setae shorter than 1 cm long; capsules usually
very dark red-violet; costae ending before subula; upper leaf cells
thick-walled 2. T. urceolatus
In Russia this species is
found in the Asian Arctic regions in relatively dry tundras and
Siberian mountains. There is also one historical record of it from
the Caucasus. When exposed to severe climatic conditions, T. mnioides sometimes forms low, dense tufts that can be difficult
to distinguish from T. urceolatus. But, T. urceolatushas bright yellow setae that strongly contrast to the red setae in
T. mnioides.
—<> Plants
in moderately dense tufts; setae 1–3 cm long; capsules dark
red-brown or pale yellow to stramineous; costae ending in subula;
upper leaf cells thin-walled 4
4.Capsules
pale yellow to stramineous with delicate exothecial cell walls,
capsule mouths after dehiscence quadrate; hypophyses as wide as
urns; rare northern species (although locally common in Yakutia
reindeer pastures) 4. T. pallidus
This species occurs in areas
of intensive reindeer farming in the northern regions of Siberia. Tetraplodon paradoxus has somewhat similar pale capsules;
however, it differs in having longer setae, smaller, lighter colored
opercula, and cleistocarpous capsules. However, the best way to
separate the two species is by the presence in T. pallidus of
stegocarpous capsules with quadrate mouths.
—<> Capsules dark
red-brown with firm exothecial cell walls, capsule mouths after
dehiscence round, hypophyses wider than urns; common in the Russian
Arctic and northern boreal zone 3. T. mnioides
This is the most common
species of Splachnaceae in Russia. It occurs throughout Siberia, but
in European Russia it is known only from the northern boreal zone. It grows on various types of dung and rotting animals. Often the
animals are so strongly decomposed that it is not possible to
identify the substrate. Tetraplodon mnioides often grows
mixed with T. angustatus, but not with the more xerophytic T. urceolatus.