© Facultad de Ciencias Bioĺgicas UNMSM. The beginning of humidity months in the "lomas" is in June, in normal climatic conditions. The bulblet species Ismene amanea es is one ofthe first in germinate in relation to others herbaceous species, that is the reason it is considered an indicator of the beginning of humidity in the "lomas". The present work achieved in National Reserve of Lachay, Prov. Huaura, Dpto. lima, present records among July of 1997 and May of 1998. The periodíc evaluatíon in situ of seedlings let to determine the foliage area variation, number of leaves, diameter and high ofthe bulb neck. Also, it was quantified the soil humídíty. The cycle phase was registered in adults plants. A relation of humíd months delay in "lomas" (August of 1997) and its last unti11998, was made. The f1uctuating temperature and humidíty recorded during "El Niño" had a consequence in rapídly development of specimens. The seedlings showed the bígger folíage area at the beginning of September (83,9 cm2 by plant) and was díminishing through October in direct relation with soil humidity. The 30% of adults plants flowered and only 40% of these complete the fructification, diminishing their capacity of sexual spread out. The increase of soil humidity, in the following months, did not have influence in germinaban of the plant against others species which restart or extended their cycle.