Opiliaceae Valeton

Genera Included: Agonandra Miers ex Benth., Anthobolus R. Br. [note: previously resided in Santalaceae s. lat.], Cansjera Juss., Champereia Griffith., Gjellerupia Lauterb., Lepionurus Blume, Melientha Pierre, Opilia Roxb., Pentarhopalopilia Hiepko, Rhopalopilia Pierre, and Urobotrya Stapf. 

Habit: Mostly terrestrial, evergreen trees and shrubs, some lianas.

Parasitism: Some known to be root parasites (Opilia and Cansjera - Hiepko, 1979).

Roots: Form haustorial connections to neighboring plants.

Stem: Parenchymatous tissues of shoot and secondary xylem containing siliceous cystoliths in scattered specialized cells or groups of cells but crystals otherwise wanting.

Leaves: Alternate (distichous), simple, entire, exstipulate, with paracytic stomates, variable in form and size, venation pinnate. Dried leaves finely tubercled by cystoliths located in the mesophyll.

Inflorescence: Cauliflorous spikes, umbels, panicles, catkins; flowers individually subtended by caducous bracts, pedicelled or sessile. "Racemes" actually more complex inflorescences because the flowers are arranged in ternate groups along the rachis.

Plant Sex: Flowers bisexual or dioecious (Agonandra and Gjellerupia)

Flowers: Monochlamydous, hypogynous, actinomorphic.
Calyx: If present, small, inconspicuous, cupular, entire-margined or with 4-5 small lobes or teeth; not accrescent. If absent, perianth represented by valvate, sometimes united tepals.
Corolla: Present in bisexual and staminate flowers, 4-5, free or connate below, valvate.
Nectary: Intrastaminal, of distinct, connate, annular, or cupular nectaries alternating with stamens.
Androecium: As many as the petals (tepals) and opposite them, free or adnate to the petals or corolla tube; anthers tetrasporangiate, dithecal, dehiscing by longitudinal slits.
Pollen: 2-nucleate, tricolporate.
Gynoecium: Compound ovary composed of 2-5 carpels, superior to 1/2 inferior; ovary topped by a simple style and a small, capitately expanded stigma (or the stigma sessile); Ovary unilocular.
Ovule: A single, pendulous ovule from the top of the free-central placenta -- except, in Agonandra, the ovule is basal and erect; anatropous, unitegmic tenuinucellar (or not differentiated into nucellus and integuments); endosperm development cellular.
Embryo, etc.: Embryology complex and diverse.

Fruit: Drupe. Pericarp thin, mesocarp more or less fleshy-juicy, endocarp woody or crustaceous.

Seed: Large, conforming to drupe. Hilum basal in a funnelshaped cavity. With small, terete embryo embedded in abundant oily and starchy endosperm, nearly as long as the seed or shorter; linear cotyledons (2) 3-4.

Chromosomes: N=10.

Alternate Family Names: Anthobolaceae Tiegh.

Last updated: 14-May-18 / dln