Mobilabium is monospecific and endemic to northeastern tropical Australia.
The species is epiphytic on rain forest trees on the plateaux at 500–1300 m. It is locally common along streams, roads, fences, and relictual trees, sometimes in exposed situations, where it is pendent and attached by a few roots.
Epiphytic herbs. Stem 3–60 cm long, erect or straggling, branching when long. Leaves 3–12 or more, widely spaced, oblong, apex acute, usually uncinate, margins often decurved, stiff, coriaceous, yellow-green. Inflorescence 2–6 cm long, racemose, 5–15-flowered; peduncle usually shorter than rachis. Flowers 5–7 mm wide, remaining open for over two days, not opening widely, cream, pale green or brownish with purple or red markings on labellum and column. Sepals concave. Petals subfalcate, slightly shorter and narrower than sepals. Labellum hinged to and hanging from upturned apex of column foot so that the disc is vertical, side lobes vertical, well developed, suboblong, acute, proximal halves of front margins strongly incurved; disc thick and fleshy, with a prominent, upwardly directed, transverse septum with a cavity on top, the cavity containing a sticky substance; spur subovoid or cylindrical. Column slightly curved and projected forward over labellum, foot at a right angle to column proper, apex uncinate; anther cap with a slightly upturned beak, pollinia four, in two closely appressed pairs on short caudicles attached to a short stipe, viscidium pyriform; stigma quadrate or circular; rostellum decurved, bifid.
No uses have been reported for Mobilabium; it is occasionally cultivated.
