Double Oxalis compressa
Mary Sue Ittner (Sat, 11 Feb 2012 08:36:22 PST)

I have added a photo of the flowers of the double Oxalis compressa to
the wiki that Ron Vanderhoff shared with me during the time we were
changing the wiki that I never got added. And I've added some more
photos of the single Oxalis compressa that came to me from Uli. Some
of these Oxalis that have more than one flower per scape can be
easily confused. In the text for Oxalis compressa on the wiki it
refers to an entry from Christiaan van Schalkwyk that explains some
of the differences between the look alikes. I once was given bulbs of
O. pes-caprae which is a huge pest in a lot of areas of coastal
California as Oxalis compressa which promptly got destroyed once I
figured it out.
http://pacificbulbsociety.org/pbswiki/index.php/…

According to Christiaan on the wiki: Oxalis compressa can be
identified by the flattened or compressed leaf stalks. Oxalis
pes-caprae has a brown bulb, without conspicuous longitudinal
grooves. It may or may not have a stem. The bulbs of Oxalis copiosa
and Oxalis haedulipes are similar: greyish and with conspicuous
longitudinal grooves. Oxalis copiosa never has a stem, while Oxalis
haedulipes always has an exserted stem.

Cape Plants describes O. compressa as like O. pes-caprae but petioles
flattened and peduncles 3-6 flowered whereas O. pes-caprae can have
up to 20 flowers. I don't know about the double forms. The O.
compressa that Uli sent me is such an amazing bright yellow flower,
but I haven't found it as easy to grow in my climate as I'd like. And
I've never gotten the one from Alberto through the BX in 2008 to
bloom. It apparently is happier in Missouri than in my conditions in
California. I guess that means we won't have to worry about it
escaping and taking over. I might be able to do better if it were
grown inside or the greenhouse, but I don't really have space for it
there. You can compare the double flowered photos of each of the
flowers now on the wiki, but I'm not sure that will help in the identification:
The photo supplied by Ron Vanderhoff labeled O. compressa
http://pacificbulbsociety.org/pbswiki/files/…
The photo supplied by Pieter van der Walt labeled O. pes-caprae
http://pacificbulbsociety.org/pbswiki/files/…

Mary Sue

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