The families of flowering plants
Including Drimyaceae Van Tiegh., Takhtajaniaceae (J. Leroy) J. Leroy
Habit and leaf form. Trees and shrubs; bearing essential oils. Self supporting. 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. Leaf development not graminaceous.
Leaf anatomy. The leaf lamina dorsiventral. Stomata paracytic. Hairs absent. The mesophyll with spherical etherial oil cells; with sclerenchymatous idioblasts. Foliar vessels absent. Minor leaf veins without phloem transfer cells (Drimys).
Axial (stem, wood) anatomy. Young stems with solid internodes. Cork cambium present; initially superficial. Nodes tri-lacunar, or bilacunar (? - according to Lammers et al. 1986, but with three traces). Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. The axial xylem without vessels.
The wood diffuse porous. The axial xylem presumably with tracheids. The parenchyma diffuse or in fine lines, sometimes terminal. Included phloem absent. The wood not storied.
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; when aggregated, in cymes and in fascicles. The ultimate inflorescence units 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). Testa without phytomelan.
Seedling. Germination phanerocotylar.
Physiology, phytochemistry. Anatomy non-C4 type. Cyanogenic, or not cyanogenic. Alkaloids present, or absent. Iridoids not detected. Proanthocyanidins present; cyanidin. Flavonols present; quercetin. Ellagic acid absent. Sieve-tube plastids S-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. Dahlgrens Superorder Magnoliiflorae; Magnoliales. Cronquists Subclass Magnoliidae; Magnoliales. APG III core angiosperms; Superorder Magnolianae (?). APG IV Order Canellales.
Species 120. Genera 9; Drimys, Belliolum, Bubbia, Exospermum, Pseudowintera, Takhtajania, Tasmannia, Tetrathalamus, Zygogynum.
Illustrations. • Drimys winteri: Bot. Mag. 80 (1854). • Tasmannia aromatica: Edw. Bot. Reg. 31 (1845). • cf. Tasmannia piperita, as Drimys: Hook. Ic. Pl. 9 (1852). • Tasmannia elongata, as Drimys: Hook. Ic. Pl. 31 (1916). • Le Maout and Decaisne: Drimys.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 20th February 2018. delta-intkey.com/angio’.