Rosselia

Rosselia Forman

Description:
Dioecious trees; bark dark brown. Leaves congested near branch apices, imparipinnate, 1–3-jugate; terminal leaflet cordiform and resembling the inflorescence bracts; pulvinuli lacking; leaflets entire; tertiary veins alternate-percurrent but also forming composite admedial tertiaries parallel to the secondaries. Inflorescences axillary and terminal, elongate and narrow, the primary axis bearing spaced peduncled cymes, each arising from the axil of a foliaceous, cordate bract.  Flowers 3-parted; calyx lobes valvate, divided nearly to base and reflexed; corolla of 3 distinct, navicular, dorsally keeled petals, valvate at apex but imbricate in middle, apex usually with inflexed apiculum; stamens equal and apparently in one series; disk and pistillode in male flowers fused to form a depressed-globose ovariodisk; in female flowers staminodes reduced and disk intrastaminal, annular; ovary 3-locular, subglobose, style long, stigma with 3 subglobose lobes. Fruit a compound indehiscent drupe, pyriform and acuminate, slightly trigonous, drying slightly wrinkled; endocarp bony, one locule developing, the 2 aborted locules compressed, in cross-section visible on periphery of pyrene and forming two articulated but non-separable plates with short, pointed, distinct apical extensions (horns).  Cotyledons apparently lobed or palmatifid and laterally reverse 2-plicate.

One sp., R. bracteata Forman, apparently endemic to Rossel Island in the Louisiade Archipelago, Papua New Guinea.

Original Publication: Rosselia Forman, Kew Bull. 49: 601—621 (1994).

Web Links:
Tropicos – Rosselia

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