T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network

Monoclea forsteri

Kingdom: Plantae\
Division: Marchantiophyta
Class: Marchantiopsida
Order: Marchantiales
Family: Monocleaceae
Genus: Monoclea
Species: Monoclea forsteri 

The liverwort family of Monocleaceae contains only one genus, Monoclea, which has one species (Monoclea forsteri) in New Zealand. This liverwort is always found growing in damp and very dark shady areas. It is dioecious meaning it has separate male and female plant.  Its thallus (vegetative body) dark green or olive green in colour and it can cover large areas of a wet damp bank.
The thallus of Monoclea forsteri branches dichotomously and becomes irregularly lobed as it spreads outwards. Where the plants grow in deep shade or are liable to flooding they are sterile, but in areas of better lighting fertile plants are abundant and in these all stages of reproduction can be found at any time of the year.
The male plants are recognisable by the antheridial (sperm-producing organ) receptacles which appear dorsally as flat cushions on the median line of the thallus. Each receptacle has some 25-30 antheridia individually sunken in flask-shaped cavities which open to the surface by a pore.
The female plants have at the mid-point of each lobe a flask-shaped cavity opening dorsally by a narrow pore and containing, at first archegonia (flask-shaped, egg-producing organ), and later 1-4 sporophytes (spore-producing phase) which project from the pore as the spores ripen. The capsule opens on a dry day by a single longitudinal slit on the ventral surface, the two edges curving backwards as the spores are shed. 

In this photo of a bank covered with Monoclea forsteri several Nematoceras rivulare orchids can be seen and one top right is in flower. (Late July)