[5] Other sources place the genus in the subfamily Diplaziopsidoideae of a very broadly defined family Aspleniaceae, equivalent to the suborder Aspleniineae in PPG I.

The sori are long, straight or slightly curved, borne in two lines along the underside of a leaf pinna.

[8] (The description "narrow-leaved" in the English name is a reflection of the original specific epithet: from Latin angustus 'narrow' and folium 'leaf'.

[9] However, later authors have regarded the two as synonymous,[3][10] so that Asplenium pycnocarpon is the first legitimate name, and hence the basionym of Homalosorus pycnocarpos.

[5] Other sources place the genus Homalosorus in the subfamily Diplaziopsidoideae of a very broadly defined family Aspleniaceae, equivalent to the suborder Aspleniineae in PPG I.

[4] It grows in moist (mesophytic) woods and ravines in neutral or basic soils, at elevations of 150–1,000 m (500–3,300 ft).