Species description:
Genus name refers to the differentiated branch and indicates the difference in form of the leaves in the main stem and the branches. Species named in honour of J. Macoun, a Canadian botanist of the late 19th century.

Reproduction:
Sporophytes occasional, maturing in late winter and spring.

Distinguishing characteristics:
The slender, usually regularly branched shoots with leaves bearing a single midrib and lacking a hair point, the non-glossy appearance and the somewhat inclined, short, sporangium are useful features.

Habit:
Forming tight to loose, dark green to light green mats that vary considerably in abundance of branches; those of deeply shaded and well-drained surfaces tending to have fewer and more elongate shoots and branches than those on horizontal damp surfaces.

Similar Species:
From H. dimorphum, H. macomii is not easily distinguished on hand lens characters, although H. dimorphum tends to be more regularly branched and is not firmly affixed to its substratum (fre­quently terrestrial while H. macounii is usually on rock). From Claopodium it differs in the very contorted dried leaves of that genus. Leskea polycarpa usually has erect-cylindric sporangia while in Heterocladium they are short and inclined. Species of Leskeella, although similar, tend to be smaller and are confined to calcareous rock while Heterocladium is frequent on non-calcareous rock.

If more than one illustration is available for a species (e.g., separate illustrations were provided for two subspecies) then links to the separate images will be provided below. Note that individual subspecies or varietal illustrations are not always available.

Illustration Source:  Some Common Mosses of BC

Synonyms and Alternate Names:
Heterocladium heteropteroides Best
Heterocladium heteropteroides var. filescens Best