Myristica Gronov.

Scientific Description

Family Myristicaceae.

Habit and leaf form. Trees; evergreen; with coloured juice (typically with red sap); bearing essential oils. Mesophytic. Leaves alternate; spiral to distichous; leathery (or chartaceous); petiolate; non-sheathing; gland-dotted, or not gland-dotted; aromatic, or without marked odour; simple. Leaf blades entire; pinnately veined; cross-venulate. Leaves without stipules. Leaf blade margins entire. Leaves without a persistent basal meristem. Vernation conduplicate. Stem anatomy. Nodes bilacunar, or unilacunar. Secondary thickening developing from a conventional cambial ring. Roots. Aerial roots present (stilt roots), or absent.

Reproductive type, pollination. Fertile flowers functionally male, or functionally female. Unisexual flowers present. Plants dioecious. Female flowers without staminodes. Male flowers without pistillodes.

Inflorescence and flower features. Flowers aggregated in ‘inflorescences’. Inflorescences axillary; either of much-branched panicles with a slender axis and the flowers arranged in cymes to subumbels, or of umbels on a short woody axis which is scar-covered and simple or 2–5-branched. Flowers pedicellate; bracteate. Bracts deciduous. Flowers bracteolate. Bracteoles persistent (usually), or deciduous. Flowers small; 3 merous; cyclic. Floral receptacle developing an androphore. Perianth sepaline; 3; 1 -whorled; joined. Calyx 3; 1 -whorled; gamosepalous; lobed (the lobes spreading to recurved); blunt-lobed; valvate; urceolate, or campanulate, or tubular. Fertile stamens present, or absent (female flowers). Androecium 5–10. Androecial members branched, or unbranched; free of the perianth; coherent; 1 - adelphous (the filaments united into a column, the column sometimes with a sterile apiculum); 1 -whorled. Androecium exclusively of fertile stamens. Stamens 5–10; diplostemonous to polystemonous; filantherous, or with sessile anthers (if anthers interpreted as sessile on the androphore). Anthers connivent, or cohering (laterally connate); linear; dehiscing via longitudinal slits; extrorse; tetrasporangiate. Pollen shed as single grains. Fertile gynoecium present, or absent (in male flowers). Gynoecium 1 carpelled. The pistil 1 celled. Carpels reduced in number relative to the perianth. Gynoecium monomerous; of one carpel; superior. Carpel incompletely closed; non-stylate; apically stigmatic (the sessile stigma minutely 2-lobed); 1 ovuled. Placentation basal. Ovules arillate; anatropous.

Fruit and seed features. Fruit fleshy (the pericarp thick and succulent). The fruiting carpel dehiscent; a monocarpellate capsule. Fruit 1 seeded. Seeds endospermic. Endosperm ruminate; oily. Seeds arillate (aril yellow to red, greatly divided). Embryo well differentiated (very small). Cotyledons 2. Embryo straight. Testa brown to black. Seedling. Germination cryptocotylar.

Geography, cytology, number of species. Native of Australia. Not endemic to Australia. Australian states and territories: Western Australia, Northern Territory, and Queensland. Northern Botanical Province.

Economic uses, etc. Myristica fragrans supplies the spices nutmeg (the seed), and mace (dried arils).