Anthoceros


Anthoceros is a genus of hornworts in the family Anthocerotaceae. The genus is global in its distribution. Its name means 'flower horn', and refers to the characteristic horn-shaped sporophytes that all hornworts produce.

Description

Species of Anthoceros are characterized by having a small to medium-sized, green thallus that is more or less lobed along the margins. The spores are dark gray, dark brown or black, this is the easiest way to distinguish Anthoceros from the related genus Phaeoceros, which produces spores that are yellow.
The sporophytes of Anthoceros are larger and much more complex than those of Riccia, Marchantia, and Pellia. It is differentiated into a foot, a constriction like intermediate zone and a capsule. There is no seta. It arises in clusters from the dorsal surface of the thallus each surrounded at the base a tubular involucre.
Anthoceros species are host to species of Nostoc, a symbiotic relationship in which Nostoc provides nitrogen to its host through cells known as heterocysts, and which are able to carry out photosynthesis. The Nostoc colonies are present on the lower ventral surface and are visible as blue-green patches which open outwards by slime pores.
This hornwort grows in moist clay soils on hills, in ditches, and in damp hollows among rocks. The adult plant body is a gametophyte.

Species

Species include: