[britishbryologicalsociety.org.uk] Identification: In size, and habit, A. ambigua is very similar to A. aloides. Plants occur as scattered individuals or in dark green to reddish-brown patches, and are typically 2 - 5 mm tall. The leaves are also very similar to A. aloides, although the nerve usually ends in the
leaf tip and rarely extends beyond it. Capsules are common in winter and spring, and they are essential for distinguishing A. ambigua from A. aloides. Without capsules,
identification using field characters alone is not normally possible. Ripe capsules are usually erect or only slightly inclined, and bear a visible membrane between the
mouth of the capsule and the peristome teeth. The calyptra is hairless. (link added by Mary Ann Machi)
Calflora:
Information on California plants for education, research and conservation,
with data contributed by
public and private institutions and individuals.
[web application]. 2025. Berkeley, California:The Calflora Database
[a non-profit organization].Available:
https://www.calflora.org/(Accessed: 01/10/2025).