diadelphous

adjective

1. arranged in two bundles or sets by the fusion of the filaments: said of stamens
2. having the stamens so arranged, as in the sweet pea

Etymology: < di- + Gr adelphos, brother < a-, copulative + delphys, womb (see dolphin); used in contrast to phratēr, brother, commonly used for cousins and other relatives and for political colleagues; + -ous