Agave flexispina

The subpopulations in the Sierra Madre Occidental in Chihuahua and Durango are documented as widely dispersed throughout the landscape (Gentry 1982). Specimens propagated from seeds in botanical gardens reproduce between 7-10 years of age, it is estimated that the fist reproduction in the species natural habitat, where rains are scarce, is double the time observed in botanical gardens, that is 14-20 years. After first reproduction the plant produces a shoot and dies, this shoot then reproduce for the first time at 12 years of age and the total reproductive span is estimated to be 55 years. Considering past and future, it is estimated that the population has decline around 20% in the last 60 years (approximately 1.5 generations) and if the current trend continues the species will reach 40% decline in the next 60 years (approximately 1.5 generations).

The generation length was calculated using the following formula: age of first reproduction + [ z * (length of the reproductive period) ], where age of first reproduction = 14, z = 0.5 and the length of the reproductive period = 55; generation length = 41.5.