Sphyrospermum munchiqueense, A-C.  A: habit.  B: calyx showing pulvinate nectariferous disc.  C: three adjacent stamens in ventral and lateral views (from Luteyn et al. 7452, type).  Sphyrospermum campanulatum, D-E.  D: flower.  E: stamen, lateral and ventral views;  note prognatheous anther base and short tubules (from Luteyn & Lebrón-Luteyn 6817, type).  Redrawn from Opera Botanica 92: 125, fig. 9.  1987.