Including Illigeraceae Bl.Excluding Gyrocarpaceae
Habit and leaf form. Trees, or shrubs, or lianas; bearing essential oils. Self supporting, or climbing. Leaves alternate; aromatic; simple, or compound; peltate (often, in Hernandia), or not peltate; if compound, palmate. Lamina dissected, or entire; when dissected, palmatifid; palmately veined; cross-venulate. Leaves exstipulate.
Leaf anatomy. Stomata present; mostly paracytic.
Lamina with secretory cavities, or without secretory cavities. Secretory cavities containing oil, or containing mucilage. Cystoliths seemingly absent. The mesophyll with spherical etherial oil cells; containing mucilage cells, or not containing mucilage cells.
Stem anatomy. Cork cambium present; initially superficial. Nodes unilacunar. Primary vascular tissue in a cylinder, without separate bundles. Cortical bundles absent. Medullary bundles absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with libriform fibres. Vessel end-walls simple. Vessels without vestured pits. Wood parenchyma paratracheal. Sieve-tube plastids P-type; type I (b).
Reproductive type, pollination. Plants hermaphrodite, or monoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes; regular; cyclic; tetracyclic.
Perianth with distinct calyx and corolla, or sepaline (?—‘of tepals’); 6–10 (3–5 in each whorl); free; more or less 2 whorled; isomerous; similar in the two whorls. Corolla not fleshy.
Androecium 3–5. Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens, or including staminodes (these in the form of 1–2 nectariferous glands outside the stamens, cf. Lauraceae). Staminodes external to the fertile stamens. Stamens 3–5; oppositisepalous (alternating with the inner perianth whorl). Anthers dehiscing by longitudinal valves. Anther wall of the ‘dicot’ type. Pollen grains nonaperturate; 2-celled.
Gynoecium 1 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium monomerous; of one carpel; inferior. Carpel stylate; apically stigmatic; 1 ovuled. Placentation apical. Ovules pendulous; anatropous; bitegmic; crassinucellate. Endosperm formation cellular.
Fruit non-fleshy. The fruiting carpel indehiscent; winged or enclosed in an inflated envelope derived from connate bracteoles. Fruit 1 seeded. Seeds non-endospermic. Cotyledons 2 (fleshy, oily, smooth or ruminate). Embryo straight.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Not cyanogenic. Alkaloids present. Iridoids not detected. Arthroquinones detected (Illigera); polyacetate derived. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid absent (Hernandia). Saponins/sapogenins absent. Aluminium accumulation not found. Sugars transported as sucrose (Hernandia).
Geography, cytology. Sub-tropical to tropical. Pantropical.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Laurales. Cronquist’s Subclass Magnoliidae; Laurales. APG 3 core angiosperms; Superorder Magnolianae; Order Laurales.
Species 54. Genera 3; Hazomalania, Hernandia, Illigera.