In nature hybrids of Rumex may be recognized by their appearance. The primary panicles sheds most of the sterile flowers but the plants continue to grow and tend to form secondary flowering panicles. Thus the hybrids are often taller than the parents and assume an untidy habit. Additionally most hybrids fail to set fruit because the flowers dry and fall off before full development of the valves (i.e. the three inner perianth segments) occurs. The few valves which do reach full size exhibit the characters of the parents in various ways. Often these hybrid nuts, even if reaching full size, are not viable and can be compressed between the fingers.