Seeds on the stem went dry

[Giorgio Pozzi]

In few days some of my plants that were rippening seeds, plied the stem
down and it came dry, the same for the seeds which stopped growing and
became yellowish and dried, the leaves are fine, the plants look fine
also.

There are three Sikokianum (?) from Chen Yi, near and very similar for
size and leaves, they all were setting seeds, but two made what I said:
seeds yellowish-dry, and spadix and stem dried, one is developing
seeds normally, with green color and big stem.

A Candidissimum in different position did the same, taking the corm out
of the soil, it was regular, no softness and some white roots.

A Franchetianum I potted  for getting pictures of  the plant and
flower, did the same.

Can anyone tell me something?


Hardiness 6a, some plants are still flowering, like Tortuosum and one
Candidissimum.
Thanks

Giorgio