Family Winteraceae

Winteraceae Lindl.

Including Drimyaceae Van Tiegh., Takhtajaniaceae (J. Leroy) J. Leroy

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. Plants hermaphrodite, or monoecious, or polygamomonoecious. Pollination anemophilous, or entomophilous.

Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; in cymes and in fascicles. The ultimate inflorescence unit cymose. Inflorescences cymes or fascicles. Flowers medium-sized; calyptrate, or not calyptrate; 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 sepals 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 carpelled (in one whorl). The pistil when other than apocarpous, 1 celled, or 2–20 celled. Gynoecium 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; an aggregate, or not an aggregate. The fruiting carpels when compound coalescing into a secondary syncarp, or not coalescing. 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 not ruminate; oily. Embryo well differentiated (but very small).

Seedling. Germination phanerocotylar.

Physiology, biochemistry. Cyanogenic, or not cyanogenic. Alkaloids present, or absent. Iridoids not detected. 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. APG 3 Order Canellales.

Species 120. Genera 9; Drimys, Belliolum, Bubbia, Exospermum, Pseudowintera, Takhtajania, Tasmannia, Tetrathalamus, Zygogynum.

Illustrations.
• Technical details: Drimys.