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Re: Nomaphila corymbosa 'compacta' questions
Naomi wrote:
"...In the store, they were labelled
"Nomaphila corymbosa 'compacta'." I've been told that "Nomaphila" is just
another name for "Hygrophila"; I think the reason why this store uses the
former nomenclature is to avoid hassles with the Dept. of Agriculture. Most
of the Hygrophila spp are banned, here, and I'm sure just having the genus
name on the packing list would be enough to send up a red flag."
Interesting conjecture, and it might be the case. It would be one way to get
a banned plant past a lax inspector. However, there is some "official"
support for the use of the name. Christopher D.K. Cook, in his Aquatic
Plant Book (the source that Tropica uses for their plant nomenclature) says
that the genus Hygrophila, as currently used, encompases the genera
Asteracantha, Cardanthera, Nomaphila and Synnema. He also satates that the
generic delimination of the tribe (taxonomic category between the family and
genus level) Hygrophileae is "much in need of revision".
The generic name Nomaphila was first used by Carl Ludwig von Blume (Blume)
in 1826, while the generic name Hygrophila was first published in 1810 by
the botanist Robert Brown (R.Br.). The species "corymbosa" has been
described under both generic names (Hygrophila and Nomaphila) - Blume
described "Nomaphila corymbosa" in 1826 and Gustav Lindau (Lindau) described
Hygrophila corymbosa (date unknown). According to the "rules" which govern
such things, when there are two (or more) generic names used to describe the
same plant, priority is given to the one which was published first - in this
case, Hygrophila (1810) takes priority over Nomaphila (1826). The same
situation exists when a later revision of a group of genera result in
several genera being grouped together under a single generic name - the
oldest validly published name becomes the "accepted" name for the whole
group.
It also helps to keep in mind that, at least in a lot of cases, the exact
placement of any species is just an "opinion" and is what one (or more)
botanists thought at a particular point in time, given their experience and
research. Later workers, with different information, might place a plant in
a different classification. Very little is set in stone. This situation
mirrors the one discussed earlier in the month regarding the genera
Eusteralis and Pogostemon.
Hygrophila species are usually emergent aquatics - they grow rooted in wet
soil and they can have leaves both above and below the waterline. In many
cases, the size and shape of the leaves will differ, depending upon whether
they are emersed or submerged. The inflorescence in H. corymbosa could be
what you are describing - the flowers grow from the point where the leaves
meet the stem, and they appear in groups. These could appear to be what you
call "tubers". Every Hygrophila species I have ever grown has been readily
rooted from cuttings, so I don't think that you would hurt anything to just
lop off the healthy top of your plants and stick them into the substrate.
Don't discard the remaining "stem" - leave it alone and you might see
dormant buds in the leaf axils start to grow, giving you more potential
cuttings to increase your stock.
When you look at a plant name and see a third name (i.e H. corymbosa
'compacta'), usually enclosed in parenthesis or sometimes capitalized
following the species epithet, it usually indicates a cultivated variety. If
it appears without any emphasis, it would mean a natural sub-species. In
this case, 'compacta' would mean a cultivated variety of H. corymbosa which
is physically smaller than the natural form. Looking at the Tropica
listings - you quite often see plant names which have three words - this
just means that a lot of what they are selling are cultivated variants of
the natural forms (and this is a good thing - it means that the nurseries
are working to select and improve the plants that they sell).
James Purchase
Toronto