Oxalis stricta
 
Yellow Wood-Sorrel

Stamen Tube

Regina
07-July-2017

The stamen tube has been split and spread flat.  There are five short stamens and five long stamens.

I am including S. europaea within a larger S. stricta.  The key to the families in Budd's Flora requires "stamens usually separate or partly so, not in a column".  This is not true.  The filaments in S. stricta are united in a column around the pistil.  I have deleted that item from the family key answers below.

Stricta: Answers to key questions in Budd's Flora leading to this species. 

stem NOT rooting at nodes; NOT [stem often rooting at nodes]

stem erect or decumbent in age; NOT [stem creeping]

 

Oxalidaceae: Answers to key questions in Budd's Flora leading to this family. 

herbs; NOT [shrubs or trees]

plants terrestrial or semiaquatic; NOT [plants aquatic; leaves submerged or floating]

plants NOT with colored milky juice

plants with more than one normal leaf

some or all leaves alternate; NOT [leaves opposite, whorled or basal]

leaves with stipules; NOT [leaves without stipules, or having glands]

leaves of 3 leaflets; NOT [leaves palmately divided]

flowers with two floral rings

flowers regular in shape; NOT [flowers irregular in shape]

calyx regular; NOT [calyx irregular, some sepals smaller than others]

each petal distinct from the others

stamens 5 or 10; NOT [stamens usually numerous]

ovary of 5 united carpels; NOT [ovary of one or more carpels, either separate or enclosed by a fleshy receptacle]

fruit not beaked; NOT [fruit with a long beak]