TOW Oxalis - responses to various postings
Robin Attrill (Wed, 12 Nov 2003 15:21:49 PST)
All,
I have a few comments on various postings, summarised below.
regards
Robin
Uli wrote.......
There is a particularly
nice tall growing plant
form Ecuador (which I traded with nothing but an accession No) with mauve
pink
flowers with very dark centres in umbels high above the leaves, it may
even
bloom year round when kept in the appropriate climate. It needed a few
years to
develop to its full beauty, I suspect that some Oxalis do NOT like to be
transplanted every year, most do not mind, though.
I presume this could be the plant listed as Oxalis Sp.-Rcb Eq-V-2 in the
Oxalis listing of the Cotswold Garden Flowers website at
http://www.cgf.net/list.html Sadly they no longer appear to sell it.
There is also Oxalis articulata which forms finger-like tuberous stems
above
ground. it produces mounds of fresh green leaves almost invisible under
masses
of pink flowers, a nice edging plant and never a weed. This one definetely
flowers all year in suitable conditions and is widespread in mild European
gardens and is perhaps hardier than expected.
O. articulata/crassipes can be weedy in the UK - it is particularly
problematic if it colonises mown grassland where mowing operations spread
fragments which can form new plants. It is generally not a problem in a
garden context.
The Wiki pages on Oxalis are very nice and I was able to identify some of
the
plants I grow (but having doubts about O. incarnata, there is nothing red
about
it as the name implies) O "incarnata"
Under certain conditions the stems are reddish
Some of the nicest Oxalis are not weeds at all but are painfully slow to
increase.
In my experience this is true of most plant genera!!!
Dave Victor wrote........
They are all grown in my standard one litre pots,
in a mixture of a soil based compost and sharp grit/sand, roughly two to
one.
I use the same mix but mostly smaller pots, mostly 9cm squares due to very
limited space. These are adequate for all but the largest species.
The second was another O. species, which turned out to be O.
gracilis.
O. gracilis, or something very similar, is sometimes sold in commerce as O.
karroica, a name which I have not found in the standard Oxalis literature or
IPNI. It is a lovely plant.
The third came to me as O. massoniana and, indeed, looked rather like that
species until it flowered. However, at the point, the flowers that emerged
were almost identical to O. versicolor: white, with a pale pink edge to a
reverse petal edge, so it appears similar to a barber's pole. Another very
pretty species, which I have tentatively identified as O. heidelbergensis.
O tenuifolia is rather similar
Incidentally, thinking about identification, many of you will grow O. 'Ken
Aslet', which has been identified under a variety of specific epithets in
the past. Last year, Mike Grant, the senior taxonomist at RHS Wisley
re-keyed the plant and confirmed it as O. melanostica.
I've held this view for many years - the spelling is actually melanosticta
Mike Mace wrote.....
There appear to be many other interesting species of Oxalis, but I've
never seen them available. For example, Barbara Jeppe's "Spring and Winter
Flowering Bulbs of the Cape" has paintings of beauties like O. tenuifolia
(long tufted stems with white flowers on top), O. helicoides (long spindly
stems with red flowers), O. convexula (looks like another alpine cushion
plant, with big salmon-red flowers), O. ciliaris (looks like an Oxalis palm
tree, with big pink flowers on top), and O. orthopoda (looks like a tiny
telephone pole covered in Oxalis leaves, with a white flower shooting out
of
the top). Where can we find these things?
Many are in cultivation - they have just not been commercialised. O
convexula is listed by Telos. Ensuring they grow in the habit found in
nature, as illustrated in the Jeppe book, is often difficult, particularly
in northern climes. Supplementary artificial light may assist.