The tightly packed shoots of this species form light green tufts 2–6cm tall, usually with abundant capsules

The leaves are 3–5mm long with a smooth margin (entire). They are drawn out to a long, thin wavy tip (ovate-lanceolate). 

Upright, cylindrical capsules are borne on a long, thick seta up to 3 cm long, and have a conspicuously long, thickened neck

T. mnioides resembles Tetraplodon angustatus but can easily be distinguished as T. angustatus has

  • strongly toothed leaves
  • shorter setae - less than 5 mm long 

Splachnum species have more shortly pointed leaves. Their capsules have different shapes and are borne on a more slender, often wavy, seta.