The families of flowering plants
Including Winteranaceae Warb.
Habit and leaf form. Highly aromatic, glabrous trees (mostly), or shrubs (rarely); bearing essential oils. Leaves evergreen; alternate; leathery; petiolate; non-sheathing; gland-dotted; aromatic; simple. Lamina entire; pinnately veined. Leaves exstipulate. Lamina margins entire.
Leaf anatomy. The leaf lamina dorsiventral, or bifacial. Stomata present; mainly confined to one surface (abaxial); paracytic (usually), or anomocytic. Hairs absent. Adaxial hypodermis present, or absent. The mesophyll always with spherical etherial oil cells (these with yellow contents, appearing as transparent dots in cut leaves); containing crystals. The crystals druses. Minor leaf veins without phloem transfer cells (Canella).
Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar, or bilacunar (with three traces, according to Lammers et al. 1986). Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow.
The wood diffuse porous. The vessels small; solitary (usualy, exclusively), or solitary and radially paired (in Warburgia). The vessel end-walls oblique; scalariform. The vessels without vestured pits; without spiral thickening. The axial xylem with tracheids; with fibre tracheids; without septate fibres. The fibres without spiral thickening. The parenchyma apotracheal, or paratracheal, or apotracheal and paratracheal. Included phloem absent. The wood not storied. Tyloses absent.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when solitary, axillary; when aggregated, in cymes, or in racemes. The ultimate inflorescence units cymose, or racemose. Inflorescences terminal, or axillary; cymes or racemes. Flowers regular; cyclic, or partially acyclic. When partially acyclic, the perianth acyclic (the petals). Floral receptacle not markedly hollowed. Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla, or sequentially intergrading from sepals to petals (depending on whether the three thick, leathery, persistent outer members are interpreted as sepals or bracts); (7–)8–15; free, or joined; 2–3(–5) whorled; anisomerous. Calyx 3 (if the outer members are not interpreted as bracts), or 4–5 (interpreting the outer whorl of petals as sepals); 1 whorled; polysepalous; regular; imbricate. Corolla (4–)5–12; when cyclic, 1–2(–4) whorled; polypetalous, or partially gamopetalous, or gamopetalous. Corolla lobes about the same length as the tube, or markedly longer than the tube (corolla connate at the base in Canella, to the middle in Cinnamosma). Corolla imbricate. Petals slender.
Androecium 6–12 (mostly), or 35–40 (Cinnamosma). Androecial members free of the perianth; coherent; 1 adelphous (completely connate into a tube, with the anthers attached on its outside). Androecium exclusively of fertile stamens. Stamens 6–12, or 35–40 (Cinnamosma); with sessile anthers (these adnate to the staminal tube). Anthers adnate; non-versatile; dehiscing by longitudinal valves; extrorse; tetrasporangiate (each with two juxtaposed bisporangiate thecae). Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; sulcate (or the aperture V-shaped or trichotomous); 2-celled.
Gynoecium 2–5(–6) carpelled. The pistil 1 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 1 locular. Gynoecium stylate. Styles 1; apical (short and thick). Stigmas 1; 2–6 lobed. Placentation parietal. Ovules in the single cavity 6–100 (two to many on each placenta); horizontal to ascending; in a single or double row on each placenta; hemianatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating. Synergids pear-shaped.
Fruit fleshy; indehiscent; a berry; 2–100 seeded (to many). Seeds copiously endospermic. Endosperm ruminate (in Cinnamosma only), or not ruminate; oily. Embryo well differentiated (small). Cotyledons 2. Embryo slightly curved, or straight. Micropyle zigzag.
Physiology, phytochemistry. Cyanogenic. Alkaloids present (one of the species), or absent. Saponins/sapogenins absent. Proanthocyanidins absent. Flavonols absent. Ellagic acid absent (Canella). Aluminium accumulation not found. Sieve-tube plastids P-type; type I (c).
Geography, cytology. Paleotropical and Neotropical. Tropical. West Indies and Florida, tropical South America and East Africa, Madagascar. 2n = 22, 26, 28.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Magnoliiflorae; Annonales. Cronquists Subclass Magnoliidae; Magnoliales. APG 3 core angiosperms; Superorder Magnolianae; Order Canellales.
Species 16. Genera 6; Canella, Capiscodendron, Cinnamodendron, Cinnamosma, Pleiodendron, Warburgia.
Illustrations. • Cinnamodendron corticosum: Curt. Bot. Mag. 100 (1874). • Canella winterana (Hutchinson). • Warburgia ugandensis: Stapf, Linn. Soc. Bot. 37 (1904).
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: 24th October 2017. delta-intkey.com/angio’.