FLORA OF ICELAND elements: Selaginella selaginoides, Lesser Clubmoss

Selaginella selaginoides; The Lesser Clubmoss is a common plant on Icelands dry heathers, scrublands and grasslands. The sporangia are placed in the upper part of fertile shoots. It is a rather small clubmoss (about 8 cm tall) that doesn't form longer prostrate stems. Characteristic are the teeth on the sporophyll leaves. The leaves are are about 3mm long.
How to recognize common Iceland clubmosses:
1) No trailing stems and no "cones on top of stems", leaves needle-shaped with smooth margins :
   Lycopodium selago (= Huperzia selago), fir clubmoss
else: go to 2)

2) No trailing stems but sporophyls (leaves with spore-forming organs in the axis of leaf and stem) on top of stems, leaves are toothed:
   Selaginella selaginoides, Lesser Clubmoss; this card
else: go to 3)

3) Long prostrate stems ("runners") and sporophyllia on top of ascending brances;
3a) leaves of ascending branches pressed on the stem:
   Lycopodium alpinum, Alpine Clubmoss
3b) leaves of ascending branches spreading from stem:
   Lycopodium annotinum, Interrupted Clubmoss

Very rare on Iceland is Lycopodium clavatum - of western Europe. It is much like Lycopodium annotinum but characteristically has a stem segment between the vegetative parts and the sporophyl-bearing part which has very small leaves, making this intersegment stem look almost nude. Split on top of this segment are two sporangial stems (hence the name clavatum).