In this article we will discuss about the morphology of anthoceros with the help of a suitable diagram.
Anthocerotae, or hornwort, is a distinct evolutionary group of thalloid liverworts, without an internal differentiation of thallus, each cell of which has a single large chloroplast and an associated pyrenoid. The ‘horn’ describes the sporophyte, a tapered structure of indeterminate growth.
Due to the presence of a single large chloroplast with an associated pyrenoid per cell and indeterminate growth of sporophyte some authors consider hornworts to be entirely different from Bryophytes and elevate these to a new division Anthocerophyta of plant kingdom. In this account is included the representative genus, Anthoceros.
This hornwort with about 250 species is widely distributed in temperate as well as tropical regions of the world. Over 25 species of this genus have been recorded from India. A. erectus is quite common in western Himalayas and A. gemmulosus in eastern Himalayas.
A. mangaloreus is extensively distributed in the hills of south India and extends up to western ghats. A. khandalensis abounds Khandala region of the Deccan plateau. A. erectus is also found growing in the plains of Bihar, UP and MP. The genus is adapted to grow in mild climatic conditions of hilly areas and is not suited to dry conditions.
The plant body is a small dorsiventral dark green prostrate thallus; which is variously lobed (Fig. 3.1 A, E), with a tendency towards dichotomous branching and forming orbicular or semiorbicular rosette. Sometimes, many gametophytes are close together and due to irregular growth semierect lobes are formed. The thallus is raised in A. erectus (Fig. 3.1B). It is like a thick vertical or ascending stalk.
The dorsal surface of the thallus is smooth but on A. crispulus there are many flat-lobed lamellae which impart the plant a velvety appearance. The thallus of A. gemmulosus (Fig. 3.1C) is spongy and bears a large number of marginal sub-spherical spongy bodies like a gemma.
