Friday, 29 January 2016

Tricky Syntrichia

A clump of Syntrichia, which was sparsely fruiting, confused me until I pulled it apart and realised there were in fact three different Syntrichia taxa all growing together. The sample was collected from the very mossy roof of Pendine's Sunbeam Diner, whilst balancing on a fence to get access to the lower tiles; not forgetting to grab a few pics while I was there! S. ruralis var. ruraliformis was very obviously different and I assumed the rest, including the fruiting material, was going to be montana (which looked to be the dominant species). But, in fact the capsules belonged to shoots of ruralis var. ruralis, which is said to fruit infrequently. Under the microscope the leaves can't really be confused, but looking at the clump both macroscopically and with a hand lens the picture was puzzling, with a range of apparent intermediate shoots present. Single-species colonies are normally straight forward, but I've not encountered this three-way association previously - at least not knowingly!
Above: Fruiting shoots and leaves taken from fruiting shoots.
Below: Leaves taken from non-fruiting shoots of S. montana [NB. the field of view is the same size for all microscope shots]


  1. That's intriguing. It might be worth dissecting the shoots carefully to check which ones have anteridia. Syntrichia montana fruits regularly and I wonder whether limited availability of males might limit fruiting in S ruralis (in which case male montana may do the job). I'm probably wrong but it would be worth a rummage.

  2. I won't ask what you were doing on a roof in that weather!

  3. Call it an urge! It was the third time I've passed there this month and it looked quiet ;-)

  4. PS those Syntrichia species are dioicous, which explains the scarcity of sporophytes in S ruralis (but not their relative regularity in S montana).
    On the subject of Syntrichia, Nick Hodgetts saw what he reckoned was S princeps on the limestone above Mumbles though without a voucher that has never been proved. It's not generally a limestone species in Britain, but one to bear in mind...

  5. I'll bear that in mind next time I'm down that way thanks.