Ascension : Conservation Weekly
Submitted by The Islander (Conservation Office) 15.04.2010 (Article Archived on 29.04.2010)

Only two weeks left of my part in the Conservation Department’s Endemic Plants Project and new findings are still being made. Xiphopteris ascensionensis,

The Smallest of Ascension’s Land Plants – Mosses, Liverworts and Hornworts   
Matti Niissalo

Only two weeks left of my part in the Conservation Department’s Endemic Plants Project and new findings are still being made. Xiphopteris ascensionensis, perhaps the trickiest to grow amongst ferns in Ascension, has finally been successfully germinated in far better numbers than during previous attempts, seemingly as a result of using very fresh spore. I’ve written before of the mossy bamboo stems where this fern can be found, but I have never mentioned the mosses themselves, fascinating as they are.

Mosses belong to one of the little studied groups of plants in Ascension. These are bryophytes, and besides mosses these include hornworts and liverworts. They are small true plants (in the narrow sense of the word) which lack vascular tissue to move water up the stem, and thus rely on moisture from rain and dew. Tens of species have been listed from Ascension, many of which are endemic, but there is so far no pictorial guide available for their identification, making it hard for the Conservation Department to work with these plants. Conservation Officer Stedson Stroud has realised this problem and is going to be trained in this field during our visit to Kew in June. Already, we have received photographs and descriptions of a variety of endemic and indigenous Ascension bryophytes from UK botanist Martin Wigginton.

Bryophytes are invaluable in pinpointing ecologic niches of more easily identified plants. For example, the beautiful grey-green liverwort Plagiochasma rupestre seems to be associated with some very rare ferns, and can be used as an indicator of an interesting plant area. Mature plants of the Xiphopteris ascensionensis often grow in clumps of genus Campylopus amongst other mosses. This new field will increase the Conservation Department’s ability to work with more plants in the wild. Some of these bryophytes could also be kept safe in the nursery if they can be identified threatened in the wild. Already our mist unit houses a few, so far unidentified mosses from Dewpond. The only native hornwort Anthoceros cristatus is actually a weed in the nursery.

                         nursery with two weeds – invasive fern Pteris cretica

                    (top, left) and the native hornwort Anthoceros cristatus (bottom)

 Ascension Island Conservation Department, Georgetown. Tel: 6359. Email:  olivia.renshaw@ascension.gov.ac, natasha.williams@ascension.gov.ac