Horneophyton lignieri: sporangium and spores

Sporangium with columella. Length 2 mm.
Groningen. HS.

Squashed sporangium with spores.
Width of the photo 1.5 mm. HS.

Sporangium with columella.
Height 2 mm. Groningen. HS.

Transverse section of a sporangium with spores.
Width 1.4 mm. HdK.

Longitudinal section of a sporangium with spores. The columella is visible at the
lower side. HdK. Width of the (composition photo 3.5 mm.