Home › Volumes › Mosses and Lichens › Herbarium

Herbarium — Part 6

The veil (calyptra) is a ragged membrane left at the base of the spore-case as the latter grows.

The spore-cases are chestnut brown, globular, without teeth. Normally they are in the crown (capitulum) of the plant, but by an elongation of an erect branch near the apex of the stem they are often left behind so as to appear to have grown from the side.

The pedicels are thick and stocky. [The Sphagnum pedicel (pseudopodium) does not have the same origin as the pedicel of other mosses].

The lids (opercula) are flattened in the form of an inverted saucer. These are normally cast off by the contraction of the spore-case wall. Sometimes a lid remains attached at one point and opens to permit spores to escape or closes to protect them. Sometimes, if wet, a lid does not fall, then the spores germinate within the spore-case and the growing embryos burst the spore-case and escape.

The spores are of two kinds--large four-angled spores (tetrahedral macrospores) and small manyangled spores (polyhedral microspores). The small spores are supposed to be the spores of a parasitic fungus which lives upon the developing spores of the moss. Two hundred and fifty-eight species in all are known, seventy-four being found in North America.