Machaerina mariscoides subsp. meyenii is a perennial plant with short rhizomes covered in pale reddish-brown scales. The stems, or culms, are loosely tufted, 45–90 cm tall, and 3.5–4 mm in diameter. They are trigonous but with one side much narrower and have scabrid (rough) surfaces. The leaves are simple, basal or nearly so, and equitant, with the upper leaves longer than the culm. The leaf blades are grayish-green and coriaceous, with entire margins and parallel veins. The apex of the leaves is subacute, and the sheaths are reddish-brown. Stipules are absent. The flowers occur in a compound panicle inflorescence, oblong in outline, 15–40 cm long, bearing 5–6 partial panicles. The lower bracts are longer than the inflorescence, with the panicle branches grouped 5–6, the longer ones up to 8 cm long. The spikelets are in clusters of 2–5, ovoid-turbinate in fruit, and 3–5 mm long. The glumes are 3–4 in number, rusty brown, with the uppermost being fertile, narrowly ovate, approximately 4–5 mm long, keeled, and with chartaceous, ciliolate margins. Flowers can be bisexual (perfect) or staminate. There are no sepals or petals. The flowers have three stamens. The ovary is superior with styles that are 3-cleft, with a subulate base, about 1 mm long, and pubescent. The fruit is an amber-brown, glossy achene, broadly ovoid to subglobose, 2–2.3 mm long, obscurely trigonous, and subsessile. Each fruit contains one seed with a thin seed coat, free from the pericarp, a basal embryo, and abundant endosperm. It is found in mesic to wet forest habitats between 150-1,220 meters.