Thursday, 21 July 2011

Great season for hornworts.

I went looking for hornworts for my 2nd year botany class this week.  There are three local sites where I can pretty reliably find Phaeoceros carolineanus, and in all the plants were present in abundance.  At two sites there were no sporophytes, but at one of these places I've never seen sporophytes.  That's strange, because P. carolineanus is described as monoicous (has male and female gametangia present on the same plant), so it ought to be able to mate and produce sporophytes. 
Phaeoceros carolinianus at Old Karori Road.

At Old Karori Road (always the best site), P. carolineanus was more abundant than usual and there were plenty of patches with very dense sporophytes. I love these cool little plants, partly I guess because they're so different from the other two bryophyte groups (mosses and liverworts).  On some of the gametophytes that had sporophytes attached, we also found antheridial chambers, so these ones were indeed monoicous, or gametophyte cosexual in the terminology we're proposing. 
The students had plenty of material to work with.  They make a whole mount of the thallus and look at the distinctive single large chloroplast in each cell, and it's always nice to be able to show them the sporophytes too.  Unfortunately it wasn't such a good time for liverworts; it's been a bit dry for the last week or two and there were no sporophytes to be found.

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