blooming now - weedy Oxalis - now O purpurea and Oeckloniana

AW awilson@avonia.com
Sat, 15 Jan 2011 12:08:53 PST
Dear Christiaan,

A description of the botanical differences between species, such as you have
given, is very useful. It complements the images we see on the Wiki. It
would be useful to include botanical descriptions there if members do not
object to the increase in the amount of text. Certainly, I would not.

Andrew
San Diego
 

> Hi All,
> Im pretty sure its Oxalis eckloniana sonderi. I think that its now In 
> the O. purpurea group.

That is definitely not O eckloniana, and O eckloniana and O purpurea are not
closely related. Unfortunately a lavender form of O purpurea has been
circulated widely under the O eckloniana sonderii label. The fact that
Thunberg originally and in error described O eckloniana var sonderi as O
purpurea  AFTER O purpurea was described by Linnaes in 1753 may also be a
problem, but this has been rectified in 1939 by Salter. (Salter reinstuted
the name O purpurea in the place of O variabilis (Jacq), and renamed the O
purpurea sensu Thunberg to O exckloniana var sonderii)

The two species are easily told apart when in flower - O purpurea have two
bracts BELOW the middle of the peduncle (flower stem), while the one or two
bracts of O eckloniana are close to the calyx, i.e. rather HIGH on the
peduncle.

Furthermore, O eckloniana belongs to the section Sagittatae. If you pull the
corolla away so that the stamens and styles are left intact, the short and
medium stamens or styles opens up and spread wide. Those of the other
sections (such as section stictophylla, to which O purpurea (L) belongs)
stay close together.

The bulbs are also different, O eckloniana usually have smooth light brown
tunics, while that of O purpurea are normally very dark to black, gummy and
irregular. There are many forms of both species and thus the leaves (number
of leaflets and shape), the degree of hairyness and other characters are
useless  for identification purposes.

The Oxalis pictured is probably O. purpurea (L).

Christiaan 


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