A speciebus omnibus generis Trichomanis hucusque cognitis absentia pilorum et parvarum squamarum in margine laminae sitorum nec non venae falsae submarginalis differt.
Stem slender, long creeping, filiform, 0.3-0.4 mm in diameter, lacking roots, covered with numerous light brown, simple, pluricellular rhizoids up to 1.4 mm long, also present on the petiole, abaxially on the rhachis, costae and veins, and sometimes along the margin of the lamina, mainly in its proximal half. Leaves distant, 1.2-3.5(-4) × (0.9-)1.2-2.8 cm; petiole (0-)1-2 mm long; lamina irregularly divided, deeply pinnatifid or bipinnatifid to subdichotomous, delicate, translucent, olive-grey with a metallic shine when dry; margin glabrous except for occasional rhizoids; base frequently rounded or obtuse, rarely cuneate; pinnae (when present) irregular, with one or two lateral segments; ultimate segments oblong to linear, 1-1.4 mm broad, their apex rounded or obtuse; venation anadromous or anisotomically dichotomous; false veinlets much reduced in number and size, up to 0.2 mm long, submarginal, oblique or some of them parallel to the midvein of the segment, sparse, isolated or even absent from some segments. Sori unknown.
The new species differs from the other species of Trichomanes subg. Didymoglossum by the light brown, long, pluricellular rhizoids that not only cover the stem but in addition are persistent and abundant on the rhachis beneath. Furthermore, the false veinlets are reduced in size and number, placed between midvein and margin and running oblique to the former, or may even be absent. The division of the lamina is irregular, and the colour of the tissue, when dry, is olive-grey with metallic shine.
Stem anatomy (Wessels Boer 1962) also deviates. A conspicuous Casparian strip is present, its cells having much thickened walls, which is not observed in other species, and the number of central tracheids is higher.A,B