Mar. 4, 2013 — For hundreds of years, plant taxonomists have worked to understand how species are related. Until relatively recently, their only reliable source of information about these relationships was the plants’ morphology — traits that could be observed, measured, counted, categorized, and described visually. And paramount among these morphological traits were aspects of flower shape and arrangement.
In the papilionoid legumes — a large, diverse group that includes the common pea and bean — most species have highly specialized, “butterfly-shaped” flowers with bilateral symmetry, fused stamens, and strongly differentiated standard, wing, and keel petals. Papilionoid genera with radially symmetric or weakly differentiated flower parts have been regarded as primitive members of the group. However, an international team of researchers have found that floral morphologies may be less reliable than other traits in determining the relationships of papilionoid species and genera. Their findings can be found in the recent issue of the American Journal of Botany. [ … continue reading ]