The families of flowering plants.
IncludingHortoniaceae A.C. SmithExcluding Atherospermataceae, Siparunaceae
Habit and leaf form. Shrubs and herbs; bearing essential oils; resinous (often), or not resinous. Mesophytic. Leaves opposite; leathery; petiolate; gland-dotted (often), or not gland-dotted; aromatic (often, resiniferous), or without marked odour; simple. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire, or serrate. Leaves without a persistent basal meristem. Domatia occurring in the family (Tetrasynandra); manifested as pockets.
Leaf anatomy. Stomata present; commonly paracytic.
Adaxial hypodermis present. Lamina dorsiventral; often with secretory cavities. Secretory cavities containing resin. The mesophyll with spherical etherial oil cells. Minor leaf veins without phloem transfer cells (Peumus).
Stem anatomy. Cork cambium present; initially superficial. Nodes unilacunar (with one to several traces). Cortical bundles absent. Medullary bundles absent. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with tracheids; with fibre tracheids, or without fibre tracheids; with libriform fibres, or without libriform fibres (the fibres often septate). Vessel end-walls oblique; scalariform, or reticulately perforated, or simple (rarely). Vessels without vestured pits. Wood parenchyma apotracheal, or paratracheal, or apotracheal and paratracheal (very variable). Sieve-tube plastids P-type and S-type; type I (a and b).
Reproductive type, pollination. Plants hermaphrodite (?), or monoecious, or andromonoecious, or gynomonoecious, or dioecious, or androdioecious, or androdioecious, or polygamomonoecious, or polygamodioecious (? — ‘commonly unisexual’). Female flowers with staminodes, or without staminodes.
Inflorescence, floral, fruit and seed morphology. Flowers solitary (sometimes), or aggregated in ‘inflorescences’; in cymes. The ultimate inflorescence unit cymose. Inflorescences axillary, or terminal (rarely); helicoid cymes, cymose or racemose. Flowers small to medium-sized; calyptrate, or not calyptrate; regular, or somewhat irregular (then somewhat oblique); cyclic, or partially acyclic. The gynoecium acyclic. Floral receptacle markedly hollowed. Free hypanthium present.
Perianth with distinct calyx and corolla, or sequentially intergrading from sepals to petals, or sepaline, or vestigial to absent; 4–50 (to ‘many’, often shedding the tips from the bud as a ‘calyptra’); free, or joined; 2–3 whorled; anisomerous; fleshy, or non-fleshy; persistent, or deciduous. Calyx when recognisable 4; sometimes 2 whorled; polysepalous; regular; fleshy; calyptrate, or not calyptrate; imbricate (decussate). Corolla 7–20(–30); polypetalous.
Androecium 10–150 (usually ‘many’). Androecial members free of the perianth; free of one another; 1 whorled, or 2 whorled. Androecium including staminodes (possibly staminodal basal nectaries, and staminode(s) between A and G). Staminodes 1–50 (? — to ‘many’); internal to the fertile stamens. Stamens 10–150 (usually ‘many’?); filantherous (the filaments short, often flattened). Filaments not appendiculate (without glands). Anthers basifixed; non-versatile; dehiscing via longitudinal slits, or dehiscing by longitudinal valves; extrorse, or introrse; tetrasporangiate. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen shed in aggregates, or shed as single grains; when aggregated, in tetrads (e.g. Hedycarya). Pollen grains nonaperturate (mainly), or aperturate (perhaps, in Macrotorus); when detectable, 1 aperturate; when aperturate, sulcate (perhaps, in Macrotorus); 2-celled (in Peumus).
Gynoecium (1–)3–100 carpelled (to ‘many’). The pistil when monomerous, 1 celled.Gynoecium monomerous, or apocarpous; of one carpel, or eu-apocarpous; superior to partly inferior (the carpels sometimes partly sunk in the receptacle). Carpel apically stigmatic; 1 ovuled. Placentation apical. Stigmas dry type; papillate; Group II type. Ovules ascending (usually), or pendulous (rarely); anatropous; bitegmic; crassinucellate. Embryo-sac development Allium-type (seemingly). Polar nuclei fusing prior to fertilization. Antipodal cells formed; proliferating (to 5–20 cells, in Peumus boldus). Endosperm formation cellular. Embryogeny asterad.
Fruit (i.e. the carpel) non-fleshy; an aggregate (in a head). The fruiting carpels coalescing into a secondary syncarp (often often partially embedded in the fleshy receptacle and/ enclosed by the hypanthium), or not coalescing. The fruiting carpel indehiscent; an achene. Fruit enclosed in the fleshy receptacle to enclosed in the fleshy hypanthium (often), or without fleshy investment. Dispersal unit the flower. Fruit 1 seeded. Seeds endospermic. Endosperm not ruminate; oily. Embryo achlorophyllous (1/1); straight.
Physiology, biochemistry. Not cyanogenic. Alkaloids present (commonly), or absent. Iridoids not detected. Proanthocyanidins present, or absent; when present, cyanidin. Flavonols present; kaempferol and quercetin. Ellagic acid absent (3 genera, 3 species). Saponins/sapogenins present (rarely), or absent. Aluminium accumulation demonstrated. Sugars transported as sucrose (in Peumus).
Geography, cytology. Temperate to tropical. Chiefly southern tropical - Central and South America, Southwest and Southeast tropical africa, tropical and Eastern Australia, Polynesia, New Zealand.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Laurales. Cronquist’s Subclass Magnoliidae; Laurales. APG 3 core angiosperms; Superorder Magnolianae; Order Laurales.
Species 150. Genera 26; Austromatthaea, Decarydendron, Dryadodaphne,Ephippiandra, Faikea, Hedycarya, Hennecartia, Hortonia,Kairoa, Kibara, Kibaropsis, Lauterbachia, Levieria,Macropeplus, Macrotorus, Matthaea, Mollinedia, Monimia,Palmeria, Parakibara, Peumus, Steganthera, Tambourissa (Ambora), Tetrasynandra, Wilkiea, Xymalos.
Economic uses, etc. Some cultivated as ornamentals (Hedycarya, Peumus), edible fruits fromPeumus, commercial timbers from many members (e.g. Chilean boldo wood from Peumus boldus).