(Quentin Cronk, Director of the UBC Botanical Garden and Centre for Plant Research has kindly offered to guestblog today -- Daniel)
This photograph was taken at Jervis Inlet, British Columbia, on a very enjoyable Botany graduate field trip with UBC bryologists Shona Ellis and Wilf Schofield (co-author of the Takakiaceae for the Bryophyte Flora of North America project), organized by graduate students Nyssa Temmel and Chris Sears. The photograph was taken standing on a boulder in a wet gulley in the persistent drizzle of a typical March day, having arrived in a hired motor boat at the head of Jervis Inlet (the site is not accessible by road, nor would it be possible to hike in). The boat was gently beached so that we could jump off into the shallows.
The moss Takakia is interesting for many reasons, not least because when discovered it was thought to be a liverwort! Hooker collected specimens of another species in the Himalayas in the mid-19th century, which Mitten described as a liverwort, Lepidozia ceratophylla. Without seeing the sporophytes (capsule bearing structures full of spores), which are rare, this was quite a reasonable identification. Sporophytes were later discovered in Alaska. These were clearly moss-like and recent DNA data have confirmed its status as a moss. The British Columbian species, Takakia lepidozioides, also occurs in both Asia and Alaska, while the other species, T. ceratophylla, is confined to Asia and Alaska.
The reason sporophytes are so rare is that there are separate male and female plants which reproduce asexually, so large patches of a single sex develop, unable to produce the sporophytes (which result from fusion of male and female gametes). All the plants in British Columbia appear to be female, so sporophytes are not expected anytime soon. The male plants may have become extinct during one of B.C.'s ice ages. The presence of an ice sheet would confine Takakia to small refuge areas. It is possible that a male spore will blow in from Asia one day and start the sexual process once more in B.C. However, this may not happen for millions of years.
The plants are very small and the leaf segments are typically only one or two cells wide. This photograph covers roughly the area of a postage stamp.
Several interesting features can be seen. It is a very wet site on a dripping rocky cliff near a waterfall in the heart of B.C.'s coastal rainforest, and the wet conditions encourage a growth of "bluegreen algae" (cyanobacteria) that produce the prominent slime. Clearly visible in this photograph are the long green leafless "stolon shoots" which allow the plant to colonise bare areas. The leaves are bifid (deeply split into two segments) and this is obvious in a few places. Also visible are a few white "rhizomatous shoots" which give rise to the normal leafy shoots. Oil bodies are present in some of the cells and this results in the plant having a cinnamon smell when dry.