Irregularity of cambium occurs in various families of woody dicotyledonous plants, mostly among the woody climbers, known as lianes, characteristic of tropical and sub-tropical forests.

The fact was studiously evaded or concealed that a dispensation had been granted by the archbishop of St Andrews for this irregularity, which could only have arisen through some illicit connexion of the husband with a relative of the wife between whom and himself no affinity by blood or marriage could be proved.

The massive irregularity of the exterior is due to the unevenness of the site.

An irregularity having been discovered in Treilhard's election, he retired, and his place was taken by Gohier.

Gregory had promised not to create any more cardinals, and when he did so, in 1408, his former cardinals deserted him and, together with the Avignon cardinals, convoked the council of Pisa, which, despite its irregularity, proclaimed in June 1409 the deposition of both popes and the election of Alexander V.