[8] The paired flowers have an unlobed or weakly lobed calyx and a corolla which is 25–50 mm long.

[5] Lysiana subfalcata is distinguished from other local (Northern Territory) species of Lysiana by the combination of its oblanceolate leaves, its non-winged pedicels, the paired flowers on a common peduncle, its non-septate anthers, the largely red corolla tube with green or yellow lobes, and the yellowish fruit that are longer than wide.

[8] The South Australian flora website[4] describes it as flowering and fruiting throughout the year, but in the Northern Territory, the Northern Territory flora website states that it flowers from March to October and fruits from April to October.

[5][6] However, the Northern Territory flora website describes it as occurring on rocky or gravelly ranges, on hills or rises, on sandplains, and on intermittent watercourses and run-on areas.

[4][6][5] Hosts in the Northern Territory are listed as including species of Acacia, Alectryon, Atalaya, Capparis, Eucalyptus, Grevillea, Pittosporum, Senna and Vachellia.