Atractocarpus heterophyllus

Atractocarpus heterophyllus (Montrouz.) Guillaumin & Beauvis.

Atractocarpus heterophyllus is a species of flowering plant in the Rubiaceae family, native to New Caledonia. It is a dioecious, small tree or shrub with distinct morphological features including lanceolate stipules, coriaceous leaves, and axillary inflorescences. The species was described in 1914 by Guillaumin & Beauvis. based on original material collected by Montrouz. The lectotype for A. heterophyllus is designated as Montrouzier 179, housed at MPU, due to the destruction of other syntypes. The plant is characterized by sexual dimorphism in its inflorescences and fruits, with male flowers in cymes and female flowers solitary.

Description

Atractocarpus heterophyllus is a dioecious, small tree or shrub reaching 1–2.5 m in height, with a monocaul or few-stemmed habit. Leaves are opposite, oblong-elliptic, glabrous, with petioles 26–42 mm long and lamina 140–220 × 50–100 mm, coriaceous, with a glossy dark green upper surface and a dull grey-green lower surface. Inflorescences are axillary, branch-like, up to 140 mm long, with male flowers in 3-flowered cymes and female flowers solitary. Flowers are ± sessile, 5-merous, with a hypanthium that is linear in males and centrally inflated in females. The corolla is urceolate, 20 mm long, with lanceolate lobes. Anthers are bilocular and dorsifixed. The fruit is a solitary, oblong-ovoid drupe, 30–60 × 25–50 mm. The species is native to New Caledonia and was published in 1914.