Re: moss and liverwort names

["James Purchase" <jppurchase at rogers_com>]

Tomoko was providing Stephan with some follow up on the possible ID of
certain mystery mosses.

It appears that the word "moss" is being confused.

Tomoko said that the Pisces book she has lists several "mosses", namely
Fissidens japonicus(japonica?) and Ricciocarpus natans. Fissidens is a
"moss" but Ricciocarpus is a "liverwort".

My copy of "Introduction to Bryology" by W.B.Schofield describes
Ricciocarpus as a  hepatic (liverwort) which floats ON the surface of quiet
waters, while Riccia is usually submerged just below the water surface. He
also describes Riella as an aquatic liverwort which grows attached to the
substrate in shallow quiet water bodies. Another liverwort associated with
water (although not specifically described as true aquatics) is Scapania
("confined to surfaces exposed to splashing or rapidly moving water").

Schofielf lists Scouleria and Hygrohypnum as true mosses which are found in
the same habitats as Scapania (close to water, not necessarily aquatic).
Fontainalis and Fissidens are two aquatic mosses mentioned (among others).
Fissidens is claimed to inhabit calcium rich water and can grow both fully
submerged or merely constantly moist. Not surprisingly, Schofield who lives
in British Columbia, doesn't mention Vesicularia in his book (it doesn't
really cover tropical species all that well).

"Bryophyte Biology", edited by Shaw & Goffinet, list Ricciocarpus and Riccia
as the two genera in the family Ricciaceae.

Regarding Riccardia, Schofield states that "some species of Riccardia grow
in extremely wet sites, but none are strict aquatics".Further on, he
continues..."Some species of Riccardia occur on rotten wood, especially when
the wood is sufficiently decomposed to retain moisture for long periods.
Other species can remain submerged for extended periods. Aneura pinguis
[another liverwort] occurs in wetlands and on lake and stream margins, and
tolerates long periods of submergence".

There are apparently many liverworts that look remarkably like mosses, and
they sometimes grow together in the same habitats, making it difficult to
differentiate them to a casual observer.

Last month, I bought a copy of "A Census of Indian Mosses" by P. Bruhl. The
book appears to be a 1982 reprint of a volume first published in 1931 (India
is described as the "Indian Empire"). It contains detailed species lists and
descriptions of mosses recorded as being found in India, Ceylon and the
Malay Peninsula, all pretty "tropical" places and likely fodder for
potential aquarium plants. Unfortunately, there isn't an illustration in the
book - its limited to word descriptions.

Fontinalis antipyretica is listed, and its distribution is given as Central
and Northern Asia, Caucasus, Europe, North Africa and North America. [no
surpise there, it is considered a cosmopolitan species]. A number of species
of Vesicularia are listed, including V. dubyana. The distribution listings
are all restricted to south east Asia [which is odd, because I have seen
other references which list Vesicularia species as also found in South
America].

Ecological information is sparse - for example nowhere in the word
description for Fontinalis antipyretica is it mentioned that it is aquatic.
What it does say is "on rocks, stones and roofs in temperate regions".
Similarly, under Vesicularia, the term "aquatic" is never mentioned - "on
forest ground in tropical and subtropical regions". But there are other
mosses listed in the book which are described as aquatic. Unfortunately,
without illustrations I'm not able to even venture a guess as to what they
look like.

James Purchase
Toronto