writes:
Given the following two names:

Tillandsia usneoides fo. longissima André, 1889
Tillandsia usneoides var. longissima (André) Mez, 1896

I suspect that neither of these is correct, see below.

To complicate the issue, IPNI has it as T. u. var. longissima André.
-- Stewart Robert Hinsley


Oh dear, it sounds as if there might be an error in IPNI that should be
checked into and reported. We need to look at the actual text for the Mez
name, to see if he transferred a forma to a var.

According to IPNI, there was a Tillandsia name accredited to Mez (T. u. forma
cretacea) on page 615 in volume 3 part 3 of Flora Brasiliensis by Carl (Karl)
Friedrich Philipp von Martius, which was published 1840-1906, in 15 volumes.
So that gives a place to start looking for other Tillandsia usneoides names.
Amazingly, that book is available online in Gallica (http://gallica.bnf.fr/).

Firstly, the other Mez name makes it clear that the author of this section of
the book is Mez, so this is probably the only place that a longissima name
with that author would have been published. The longissima name is there, but
it is clear from the way it is formatted that the intention was just to cite
a previously published name of a forma, so IPNI and Martius disagree about
whether André published a var. or a forma.

It will therefore be necessary to look at the earlier publication to see if
it was a forma, in which case IPNI should be corrected. The name is listed as
appearing on page 64 of the publication "Bromeliaceae Andreanae", which is a
book by Edouard-Francois André, published 1889. I can't check this further
because I don't have access to a library just now that has that book.

I suspect that this confusion might have come about because André didn't
specify the rank of his infraspecific taxa, as many authors around that time
or earlier did not. Thus, article 35.4 might apply "35.4. If in one whole
publication ..., prior to 1 January 1890, only one infraspecific rank is
admitted, it is considered to be that of variety unless this would be
contrary to the author's statements in the same publication." Thus the
editors of IPNI would have translated his names to varieties. IPNI probably
should have another entry added "Tillandsia usneoides f. longissima Mez,
1896" (André's name does not appear because the rank has changed.)

By the way, I¹ve learned from corresponding with the editors of IPNI that
their policy is to not list formae within vars, so if someone published
³Tillandsia usneoides var conspecta f. longissima², for example, it would
appear in IPNI as ³Tillandsia usneoides f. longissima². It is possible that
André published forma longissima within a higher infraspecific taxon.

Nadia Talent

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Nadia Talent
Department of Botany, University of Toronto,
25 Willcocks Street, Toronto, M5S 3B2, Canada
Fax +1 416-978-5878
Also: Department of Natural History
Royal Ontario Museum, 100 Queen's Park West, Toronto, M5S 2C6