save the Blue Tier
tasmanian liverworts - acrobolbacaeae
goebelobryum unguiculatum
1. liverwort sporophytes emerging from bare ground
Until recently Goebelobryum unguiculatum was considered a monotype in Tasmania with 2 forms¹, long spined with dorsal stem exposed and short spined with dorsal stem covered by leaves. In their 2012 paper Engel and Glenny² (E&G) described the short spined form as a new species, G. vermiculare.
Our G. unguiculatum specimen was discovered on private property at Port Sorrell, a section of which had been mowed and set afire to encourage germination of orchid seeds. The fire had burnt off most of the gametophytes above ground and remaining nearby populations were killed by the heat and bleached by the time we collected specimens.
However the underground reproductive parts (marsupia) were alive and produced vast amounts of fruiting bodies on otherwise bare ground to the extent patches 300mm across were near white (pix 2) from the setae (stalks carrying the fruiting body). Fruiting is considered to be rare for the species³ so we were fortunate to be able to record the event and collect specimens.
2. massed sporophytes |
3. spores |
4. capsule walls |
5. capsule wall TS |
6. elater |
7. cells |
8. capsule dehiscing |
9. marsupium |
The sporophytes are interesting not least because fruting appears to be uncommon (although a form in NZ goes to the other extreme and is reported to fruit throughout the year³). Fire may be a necessary percursor to fruiting and buried parts are reported to be capable of regenerating. In this case the small local area was set afire in April to encourage germination of orchid seeds. About 2 months later patches burnt of ground bore vast quantities of sporophytes.
Fruiting differs from the more common species we have observed in the following ways:
- capsules have only a pair of valves rather than the usual four (although we have been told that this could range from 2-6 valves for some species)
- sporophytes persist over several days releasing spores through a pair of slits along the side (pix 8); this is based upon our own experience of soil cores we took as well as that of the property owner's observation in the field
- capsules do not open from the top - dehisced capsules remain intact after all the spores are released. We speculate that the capsule contracts along the long axis when dry forcing open the two slits to release spores
- capsules appear to be fairly tough as they would need to be to poke through soil; capsule walls comprise of 5 layers totalling around 65 um thick (pix 5)
We have not been able to study cell oil bodies as gametophytes collected had been killed by the heat of nearby fire several weeks earlier. E&G report this as usually 2-4 fine-to-coarse granular elliptic to spherical bodies.
We hope to visit the site some months later for further observations.
Specimens are being distributed to several herbaria including HO.
We are grateful to P. Collier for providing pix 1 and 2 as well as permitting us to collect specimens from his property.
References
-¹University of Tasmania key to liverworts
-²Engel, JJ and Glenny, D., 'Austral Hepaticae
48. Goebelobryum Grolle (Acrobolbacaeae)' - Nova
Hedwigia 95: 319-336
-³ NZ Plant Conservation Network (.pdf file)
Page URL: http://www.bluetier.org/Liverwort2/goebelobryum-unguiculatum.htm