Oxalis in bloom

diana chapman rarebulbs@earthlink.net
Tue, 08 Apr 2003 08:48:53 PDT
Dear Mary Sue:

The identity of your oxalis as O. caprina is a close as I can get.  It's
difficult to identify oxalis at all, and especially if you can't see the
bulb.  One caveat -- oxalis are very variable within each species, and they
are very prone to edaphic changes; i.e. if you grow the same plant in
different conditions, they will display different growth habits, especially
flowering time, stem length, etc.

Here's a little bit from the Salter monograph:

"Bulb ovoid, about 1.5cm long, more or less beaked at the apex with brown
(smooth - my addition) outer tunics..... Leaves 2-20, basal or apically
congested on a very short stem ... petioles usually 2-5 cm long; leaflets
3 -- bilobed to about the middle or less .... peduncles 2-4 flowered, basal
or very rarely lateral on a short stem, often twice as long as the leaves
.... pedicels 2-5 cm long.  Corolla glabrous 1.3-1.9 cm long, pale violet
... with a greenish tube."

I should also point out that the characteristic of the flowers being in an
umbel or having two or more flowers to a stem is less common among oxalis
than having a single flower to a stem, and is considered to be a more
rudimentary form, so if  your plant shows this characteristic it narrows
down the choice considerably.  There are several other candidates, however,
but for proper identification it is necessary to see the sepals, if there
are bracts on the peduncle, and the bulb itself.  Even then, identity isn't
certain. Michael and I spent an entire winter beating our brains out trying
to identify some of the species in his collection.  I managed to pin down
eleven after spending many, many hours on it.  He told me he wore out an
entire Salter that winter!  Salter is all we have;  it is difficult to use,
and is far from complete.  I have many species that don't fit anywhere (not
even close!).


----- Original Message -----
From: "Mary Sue Ittner" <msittner@mcn.org>
To: "Pacific Bulb Society" <pbs@lists.ibiblio.org>
Sent: Monday, April 07, 2003 9:01 PM
Subject: Re: [pbs] Oxalis in bloom

Dear Diana and Ann Marie,

Thanks for your comments on the mystery Oxalis. Diana, your possible
identification has me a bit puzzled. If I look at the Cape Peninsula Field
Guide (one of my least favorite of the Kirstenbosch guides) there is a
drawing of Oxalis caprina that looks like my plant. The text says it blooms
Mar. to May (Sep to Nov that would be in my hemisphere.) Last year this
plant bloomed for me in March and April and as I said this year it is still
going strong from an October start. One that appeared in my unknown pot
just started blooming last month.

In the Cape Plants book which unlike the Encyclopedia does include Oxalis,
Oxalis caprina is described as a small weak geophyte, stem absent or very
short. It says bloom is Apr. to June. Otherwise it sounds right. But this
one definitely has a stem as the new pictures show.

Second Mike Mace gave me some extra bulbs of Oxalis MV4674 described as
3/4" pink flowers, tiny tufted plants, tiny lvs. Michael Vassar said it was
caprina when I wrote and asked. It bloomed for me last year in September
and October, but didn't bloom this year and has already gone dormant. I
can't remember what it looked like, but I don't think it looked like the
one I am asking about. I know that there can be a lot of variation in the
different species so I am not ruling that out as a possibility.

For Ann Marie, the flowers are 2¼-3¼ cm. (not quite a inch to 1¼ in.) in
diameter (a bit tricky to measure as they sometimes are folded). The leaves
are slightly smaller. The effect looking at this plant is a bit like a
maidenhair fern, very airy. I added these two pictures to the mystery page
so you can get a better look at the flower and the stem.


Mary Sue

Mary Sue Ittner
California's North Coast
Wet mild winters with occasional frost
Dry mild summers

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