Species at Risk

Haller's apple moss

Bartramia halleriana

What is Haller's apple moss?

Mosses are green plants that often grow in a low, dense mat in moist, shady areas such as on the base of tree trunks, rocks, logs or soil. They do not have true roots to absorb nutrients and water. Instead, their stems are covered with tiny leaves that absorb water and nutrients like a sponge. Mosses use spores, not flowers or seeds, to reproduce themselves.

Haller's apple moss
Haller's apple moss
© Parks Canada / René Belland / 1999

Mosses have two phases in their life cycle. The first phase is the gametophyte (or plant that produces gametes - male and female reproductive cells). It is an obvious, leafy green plant. Male and female gametes from this plant produce the second phase, the sporophyte (plant that produces spores). This plant consists of a thin stalk supporting a capsule filled with spores. When the spores are mature, the capsule opens and releases the spores, which blow away to start new gametophyte plants.

Haller's apple moss ( Bartramia halleriana ) is a small to medium-sized moss (4-14 cm tall) that is green to yellowish or brownish-green in colour. It is a monoicous plant, meaning that each plant has both male and female gamete-producing structures. In Canada , this species frequently produces a lot of spores.

Haller's apple moss grows on ledges, in crevices of shaded, forested cliffs, at the base of overhangs and where rock slides of acidic bedrock occur at lower elevations in the mountains. Extensive areas of seemingly suitable habitat are found in the mountains of western Canada , but the plant has not been found beyond these few sites. This suggests that factors other than suitable habitat may restrict its distribution.

Where does Haller's apple moss live?

In North America, Haller's apple moss is found only in western Canada . One location in Alberta ( Jasper National Park ) and two locations in eastern British Columbia (just west of Jasper National Park ) are currently known. It was also documented in Wood River, British Columbia, in 1826 by a botanist travelling with voyageurs. It has not been found there since that time.

Outside North America, Haller's apple moss occurs in Europe, Asia, southern South America, Hawaii, Australia and New Zealand.

What's the status of Haller's apple moss?

In Canada, Haller's apple moss has been assessed as threatened by COSEWIC, and is protected under federal law by the Species at Risk Act. This is due to the small number of locations and population size. Alberta has ranked it as the highest category of conservation concern (S1). British Columbia has not ranked mosses, but this species would likely also be in the highest category. Worldwide, Haller's apple moss is not at risk.