Neotropical Opiliaceae

Description

Trees or shrubs. Leaves alternate, simple, margin entire; without stipules; petiolate. Inflorescences axillary or cauliflorous, rarely terminal. Flowers small, inconspicuous, actinomorphic, mainly bisexual, sometimes unisexual (plants then dioecious), 4-5, free or connate at the base; stamens 4-5, epipetalous; ovary superior, immersed in a lobed disk or diskless, unilocular. Fruit drupaceous.

Notes on delimitation

• Engler (1872) recognised Agonandra in the Olacaceae, and in 1897 he accepted the family Opiliaceae established by Valeton (1886).
• Molecular phylogenetic studies have shown the Opiliaceae to be the most strongly supported, monophyletic group in Santalales (Hiepko, 2000).

Distribution in the Neotropics

Opiliaceae comprises 10 genera and 33 species worldwide with only one genus (Agonandra) with 10 species in the Neotropics. Agonandra is distributed from Mexico to northern Argentina. In Brazil there are five species in different vegetation types (Marquete, 2005).

• A. brasiliensis Miers ex Benth. & Hook.f. occuring in forests and deciduous forests and savannas:  A. brasiliensis subsp. brasiliensis - (Panama, Colombia, Venezuela, Guiana, Brazil, Bolivia, Paraguay), and A. brasiliensis subsp. racemigera Hiepko - (Colombia, Venezuela).
• A. excelsa Griseb. - (Ecuador, Peru, Brazil, Bolívia, Paraguay, Argentina).
• A. fluminensis Rizz. & Occh. - (Brazil).
• A. goldbergiana Hiepko - (Guatemala).
• A. macrocarpa L. Williams - (México, Honduras, Nicaragua, and Costa Rica).
• A. obtusifolia Standley: A. obtusifolia subsp. obtusifolia - (Mexico), and A. obtusifolia subsp. conzattii (Standley) Hiepko - (Mexico).
• A. ovalifolia Miranda - (Mexico).
• A. peruviana Hiepko - (Ecuador, Peru, Brazil).
• A. racemosa Standl. - (Mexico, Guatemala, Honduras, and El Salvador).
• A. silvatica Ducke - (Ecuador, Peru, Bolivia, Guiana, Brazil).

Distinguishing characters (always present)

• Trees and shrubs with irregular crown (in the Neotropics).
• Leaves simple, alternate, without stipules.
• Fruit one-seeded, with fleshy mesocarp and endocarp coriaceous to woody.

Other important characters

• Leaf margin entire and petioles in some cases elongated.
• Flowers dioecious.
• Male and female flowers with differentiated disks.

Number of genera

• Opiliaceae is a pantropical family. The highest diversification of the family is found in Old World with nine genera, and only one genus in the Neotropics (Agonandra Miers ex Benth.).

Status

• Agonandra - native.

General notes