http://www.lanra.uga.edu/peanut/knowledgebase/

Reproductive stage of groundnut

Flowers are born on inflorescence located in the axils of the leaves. Flowers are never at the same node as vegetative branches, although very short internodes on some plants may make it appear that they are. Environmental conditions may cause the transformation of reproductive axes into vegetative axes, but not the reverse. The first flowers appear from 4 to 6 weeks after planting. Each flower is subtended by two bracts; the lower, on an axis of the inflorescence and the upper in the axil of the lower bract. The flower contains five petals: a standard, two wings, and two petals fused to form a keel. There are two calyx lobes, an awnlike one opposite the keel and a broad opposite the back of the standard. The flower has 10 stamens, two of which are usually not fully developed. The pistil consists of an ovary, style, and stigma. Anthesis and pollination usually occur at sunrise with pollination taking place within the closed keel of the flower.