Pittosporum flocculosum is a small tree that typically grows between 4 to 11 meters tall, characterized by young parts that are pale brown to whitish and strigose-tomentose. The stems have branches with a whitish to pale brown flocculose-strigose to glabrate texture. The leaves are simple and alternate, with oblong-elliptic, oblong-oblanceolate, or oblanceolate blades ranging from 10 to 30 cm long and 2.3 to 9 cm wide. The leaf apex is generally obtuse to rounded and sometimes emarginate, with an attenuate base. The upper surfaces of the leaves are glabrous with slightly impressed veins. In contrast, the lower surfaces are sparsely to moderately covered in whitish flocculose-strigose hairs, with mature leaves occasionally becoming subglabrate. The leaves are either chartaceous or coriaceous in summit populations, exhibiting entire, sometimes revolute margins. Lateral veins appear in 13 to 20 pairs, and petioles range from 0.6 to 5 cm in length. The unisexual flowers appear in axillary or cauline simple corymbose inflorescences consisting of 6 to 10 flowers. The inflorescences are pale brown to whitish strigose-tomentose with peduncles about 6 to 16 mm long and pedicels 1 to 3 mm long. Each flower’s calyx is narrowly cup-shaped with five distinct, ovate sepals that are 1.5 to 2.5 mm long and pale brown tomentulose. The corolla comprises five white petals, each 11 to 13 mm long. The stamens were not observed. The plant has a superior ovary with two carpels and 2 to 3 cells, situated on a short gynophore and exhibiting parietal placentation with numerous ovules arranged in two rows per placenta. The style is singular with a capitate stigma. The fruit is an ovoid to subcuboid capsule measuring 20 to 32 mm long. Immature capsules are pale brown tomentose, becoming sparsely whitish tomentose upon maturation. The apex of the capsule is rounded to obtuse, with a persistent style that is 2 to 4 mm long. The woody exocarp is 3 to 4 mm thick with a median furrow and a surface that ranges from shallowly to deeply rugose-tuberculate, sometimes appearing merely rugulose. Each capsule contains about 12 to 20 irregularly angled and compressed black seeds, measuring 6 to 8 mm long. It is found in mesic forests and occasionally on open ridges in wet forests between 270-790 meters.