The root meaning of the English word 'forest' is etymologically derived from the latin 'forestem silvam' and has had it's current meaning “a large area of land covered with trees and plants” at least since the 9nth century. Biology proposes that all properly drained lands left to themselves will eventually become forested.
Cryptoforests can be preliminary defined as:
1) Unknown forests
(forests nobody knows about)
2) Unappreciated forests
(forests that are regarded as zones of waste and weed)
3) Precognitive forests
(lands that are on the brink of becoming forested)
4) Feral forests
(planted tree zones, for instance along motorways or for agroforestry, that have been allowed to become wild to the point that their wildness has started to overshadow their original function)
5) In limbo forests (areas that might or might not be called forests for various reasons; states of vegetation for which lay-language has no words; category might include overgrown garden plots and exceedingly small forests)
The concept of a 'cryptoforest', like the concept of 'weed' is not a biological way of relating to nature but a cultural one.
The cryptoforest concept came about in the spirit of psychogeography, urban exploration and the search for the 'native' state of environments inside manmade structures. Cryptoforests illustrate biological resilience and regeneration. In the first use of the word, cryptoforests were taken to mean those fallowed, forested lands that could serve as the seeds and catalysts for full urban reforestation.