Lejeunea tapajosensis is a common tropical South American species with caducous
1 mm long, caducous on the old branches, intense on the young branches, distributed on the pulvinus, margin with leaflets, sepals and legumes.
0.5 mm long, caducous on the old parts, intense on the young branches, distributed on the branches, stipules, petioles, rachis, leaflets, inflorescences, bracts, pedicels, margin with sepals and abaxial surface with the petals.
Stipules green, linear, obsolet, 4-12 X 0.5-2 mm, caducous.
0.5 mm long, caducous. Leaves 2.2-11.4 cm long; pulvinus yellowish to vinaceous, pilose, c.
Leaves caducous or not caducous, but never fragmenting ...
Leaves caducous, apex bifid and ventral margin with one or more teeth.
Leaves not caducous, apex bifid and ventral margin entire.
Asexual reproduction by small propagula from ventral leaf surfaces or absent (rarely by caducous leaves: couplet 52) ...
Asexual reproduction by caducous leaves, by leaf fragmention, or absent ...
Leaves alternate, caducous
; short-petiolate; blades elliptic, pinnately veined, margin entire, pubescent on both surfaces.
Flowers in terminal or reduced axillary racemes; bracts several grading upward in size, or one, mostly small and persistent, sometimes leaflike and caducous
; bracteoles 2.