Family Atherospermataceae

Atherospermataceae R. Br.

~ Monimiaceae

Habit and leaf form. Trees, or shrubs. Leaves opposite; petiolate; gland-dotted, or not gland-dotted (?); aromatic; simple; exstipulate.

Leaf anatomy. Stomata present; paracytic.

Lamina dorsiventral. The mesophyll not containing mucilage cells. Minor leaf veins without phloem transfer cells (Doryphora, Laurelia).

Stem anatomy. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring. Vessel end-walls oblique; simple (with up to 100 bars). Primary medullary rays narrow. Sieve-tube plastids P-type; type I (a).

Reproductive type, pollination. Plants hermaphrodite, or monoecious, or dioecious, or polygamomonoecious.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary; when aggregated, in cymes. The ultimate inflorescence unit cymose. Flowers regular, or somewhat irregular; partially acyclic. The gynoecium acyclic. Floral receptacle markedly hollowed. Free hypanthium present.

Perianth with distinct calyx and corolla, or sepaline, or vestigial, or absent (‘apetalous’); when present, 4 (2 + 2), or 6–20 (?); 2(–3) whorled. Calyx 1 whorled. Corolla when present, 7–20 (or more); 1 whorled.

Androecium in male flowers 12–100 (? — ‘many’). Androecial members branched, or unbranched (?); when few, 1 whorled, or 2 whorled (in one or two ‘series’). Androecium exclusively of fertile stamens, or including staminodes (in the hermaphrodite flowers of Doryphora). Stamens (4–)6–100 (‘definite’ or ‘indefinite’); when ‘definite’, alternisepalous (when K and C determinable, or opposite the perianth segments). Filaments appendiculate (each with a pair of glandular scales at the base). Anthers adnate; dehiscing by longitudinal valves (the flaps attached at the tops of the thecae); extrorse; appendaged (by extension of the connective), or unappendaged. Pollen grains aperturate; 2 aperturate, or 3 aperturate; sulculate.

Gynoecium 3–100 carpelled (i.e. to ‘many’); apocarpous; eu-apocarpous; superior to inferior (the carpels sometimes sunk in the receptacle). Carpel with a lateral style, or with a gynobasic style; 1 ovuled. Placentation basal. Ovules ascending; anatropous.

Fruit non-fleshy; an aggregate. The fruiting carpel indehiscent; an achene. Seeds endospermic. Endosperm oily. Embryo well differentiated (small). Embryo straight.

Physiology, biochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid absent. Saponins/sapogenins absent. Aluminium accumulation not found.

Geography, cytology. Temperate to tropical. Australia, New Guinea, New Zealand, New Caledonia, Chile. X = 22.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Laurales. Cronquist’s Subclass Magnoliidae; Laurales. APG (1998) basal order. APG 3 (2009) Order: Laurales.

Species 12. Genera 6; Atherosperma, Daphnandra, Doryphora, Laurelia, Laureliopsis, Nemuaron.

Economic uses, etc. Edible fruits (Laurelia).

Illustrations.
• Technical details: Glossocalyx (Thonner).
• Technical details: Atherosperma, Doryphora (Lindley).

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