ameristic

am·er·is·tic

(am-ĕ-ris'tik),
Endowed with amerism; not dividing into parts or segments.
References in periodicals archive ?
A high proportion of prothalli formed antheridia in very early stages of development: by week 6, nearly 50% of the gametophytes were male, spatulate, ameristic, 40-50 cells in size; and nearly 90% by week 8; this proportion changed little over the following weeks; gametophytes grew slowly and never reached cordate shape.
There are two basic morphologies among gametophytes of Ceratopteris richardii, the large meristic hermaphrodite and the small ameristic male.