Sphenolobus minutus
Marchantiophyta
Sphenolobus minutus (Anastrophyllaceae)
Comb Notchwort
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Frequent
Distinguishing Features
Slender, thread-like, sparingly branched, yellowish-brown to olive-green shoots, often in loose mats, with strongly concave, deeply bilobed (0.3-0.5x length), slightly asymmetric leaves with acute lobes. Shoot tips often narrow and attenuate. Gemmae occasionally present (reddish-brown to green) in clusters at tips of attenuate shoots
Similar species
Similar to several other species/genera with thread-like shoots and concave, bilobed leaves. Under a microscope, it can be immediately separated from all of these by the uniformly thick cell walls and, especially, the concentric rows of quadrate to rectangular cells emanating from the leaf lobe tips (other species with irregularly placed, usually rounded cells). Macroscopically, it may be confused with Barbilophozia sudetica, but is distinguished by the placement of leaves around the stem rather than often primarily on one side (i.e., secund). Differs from Sphenolobus saxicola, a rare species of far northwestern BC, in its smaller size (shoots 0.4-1.5 mm wide, vs. 1.2-3 mm wide in S. saxicola), slightly smaller leaves (0.4-0.7 mm, vs. 0.5-0.8 mm in S. saxicola), and occasional presence of gemmae (always lacking in S. saxicola). Anastrophyllum assimile is also similar to S. minutum, but is a darker blackish to blackish-brown colour and the dorsal lobe of the leaves is slightly decurrent along the stem.
Habitat
Wide variety of wet to mesic, open to shaded habitats, but most frequent on acidic rocks, cliffs, and ledges; also terrestrial in subalpine heath, on peaty slopes, or on hummocks in bogs. Occasionally on decaying wood or tree bases.
Associated species
Barbilophozia hatcheri, Schljakovia kunzeana, Schljakovianthus quadrilobus, Dicranum spp., Cephalozia bicuspidata, Gymnomitrion obtusum, Mylia taylorii, Sphagnum spp., Ptilidium ciliare, Scapania americana, Tritomaria quinquedentata