Winteraceae Lindl.

Habit and leaf form. Trees and shrubs; bearing essential oils. Mesophytic. Leaves alternate; spiral (rarely subverticillate); `herbaceous', or leathery; petiolate; non-sheathing; gland-dotted; aromatic; simple; epulvinate. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire. Leaves without a persistent basal meristem.

Leaf anatomy. Stomata paracytic. Hairs absent.

Lamina dorsiventral. The mesophyll with spherical etherial oil cells; with sclerencymatous idioblasts. Minor leaf veins without phloem transfer cells (Drimys). Vessels absent.

Stem anatomy. Cork cambium present; initially superficial. Nodes bilacunar (with three traces, according to Lammers et al. 1986), or tri-lacunar (?). Internal phloem absent. Secondary thickening developing from a conventional cambial ring. `Included' phloem absent. Xylem presumably with tracheids; without vessels. Wood parenchyma apotracheal (diffuse or in fine lines, sometimes terminal). Sieve-tube plastids S-type.

Reproductive type, pollination. Hermaphrodite, or monoecious, or polygamomonoecious. Anemophilous, or entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in `inflorescences'; in cymes and in fascicles. The terminal inflorescence unit cymose. Inflorescences cymes or fascicles. Flowers medium-sized; regular to somewhat irregular; cyclic (?); pentacyclic to polycyclic. Free hypanthium absent. Hypogynous disk absent.

Perianth with distinct calyx and corolla; (4-)7-50 (to `many'); 2-4 whorled; isomerous, or anisomerous. Calyx 2-4(-6); 1 whorled; polysepalous, or gamosepalous (then the petals basally connate or totally concrescent); unequal but not bilabiate, or regular; not persistent; calyptrate, or not calyptrate; valvate. Corolla (2-)5-50; 1-3 whorled; polypetalous, or partially gamopetalous (the outer whorl sometimes joined); imbricate; unequal but not bilabiate, or regular.

Androecium 15-100 (to `many'). Androecial members maturing centrifugally (but initiated centripetally); free of the perianth; free of one another; 2-5 - whorled. Androecium exclusively of fertile stamens. Stamens 15-100; laminar (often), or filantherous. Anthers adnate; non-versatile; dehiscing via longitudinal slits; extrorse, or latrorse, or introrse (sometimes the `sides' of the thecae directed apically); tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with more than one middle layer (2 to 4); of the `basic' type. Tapetum amoeboid, or glandular. Pollen shed in aggregates, or shed as single grains; usually in tetrads. Pollen grains aperturate; 1 - aperturate; ulcerate; 2-celled.

Gynoecium (1-)3-20 (in one whorl); monomerous, or apocarpous, or syncarpous; of one carpel (sometimes), or eu-apocarpous, or semicarpous, or synovarious (i.e. carpels free, or partly or wholly connate); superior. Carpel (when monomeric/apocarpous) fully closed, or incompletely closed; non-stylate, or stylate; with a longitudinal stigmatic surface, or apically stigmatic; 1-100 ovuled (to `many'). Placentation marginal, or dispersed. Ovary (when more or less syncarpous) 2-20 locular. Stigmas 2-20; wet type; papillate; Group III type. Placentation when syncarpous, axile. Ovules 1-50 per locule; non-arillate; anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; persistent. Synergids hooked (with filiform apparatus). Endosperm formation cellular.

Fruit fleshy, or non-fleshy; multiple, or not multiple. The units when compound coalescing into a secondary syncarp, or not coalescent. The fruiting carpel dehiscent, or indehiscent; a follicle, or baccate. Fruit when syncarpous dehiscent, or indehiscent; a capsule, or a berry. Seeds copiously endospermic. Endosperm ruminate (Degenaria), or not ruminate; oily. Embryo well differentiated (but very small).

Seedling. Germination phanerocotylar.

Physiology, biochemistry. Cyanogenic, or not cyanogenic. Alkaloids present, or absent. Iridoids absent. Proanthocyanidins present; cyanidin. Flavonols present; quercetin. Ellagic acid absent. Anatomy non-C4 type.

Geography, cytology. Temperate to tropical. Malaysia to the Pacific, Eastern Australia, New Zealand, Central and South America. X = 13, 43.

Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren's Superorder Magnoliiflorae; Magnoliales. Cronquist's Subclass Magnoliidae; Magnoliales. Takhtajan's Subclass Magnoliidae; Magnolianae; Magnoliales. Species 120. Genera 9; Drimys, Belliolum, Bubbia, Exospermum, Pseudowintera, Takhtajania, Tasmannia, Tetrathalamus, Zygogynum.

Illustrations. winte194.gif

Additional, to be intercalated. Flowers calyptrate, or not calyptrate.