FIGURE 1 in A systematic classification of Ephedraceae: living and fossil

FIGURE 1. Suggested relationships of Ephedraceae based on the reduction and sterilization evolutionary hypothesis. A, showing the loosely arranged female spike of Siphonospermum with pedunculate FRUs; B, showing the lax female spike of Prognetella and Chengia with sessile FRUs and obvious internodes; C, showing the compact female cone of Liaoxia with multiple pairs of fertile bracts; D–E, showing the compact female cone of Gurvanella, Erenia, Alloephedra, Amphiephedra, Beipiaoa, and Ephedra having only the uppermost pair of fertile bracts but varying in number of bract whorls and FRUs. FRU, female reproductive unit; b, bract; pa, primary axis.