The families of flowering plants
Including Diphylleiaceae Schultz-Schultzenst. (p.p.), Ranzaniaceae.
Habit and leaf form. Herbs. Biennial; with a basal aggregation of leaves; rhizomatous (the rhizome and roots more or less fleshy). Leaves alternate, or opposite; petiolate; simple, or compound; peltate, or not peltate; when compound, ternate. Lamina when simple, dissected; palmatifid (or bipartite); palmately veined; cross-venulate. Leaves exstipulate.
Leaf anatomy. The leaf lamina dorsiventral. Stomata present; anomocytic. Minor leaf veins without phloem transfer cells (Jeffersonia, Podophyllum).
Axial (stem, wood) anatomy. Primary vascular tissue comprising a ring of bundles, or comprising two or more rings of bundles, or consisting of scattered bundles. Internal phloem absent. Cortical bundles present. Medullary bundles present. Secondary thickening absent (even from the rhizome, according to Tamura 1972).
Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when aggregated, in cymes and in umbels, or in spikes. Inflorescences terminal; cymose and subumbellate. Flowers regular. Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla (usually, but the sepals sometimes petaloid), or absent (Achlys); 10–24; 3–6 whorled. Calyx 4–15; 1–4 whorled (?); polysepalous (the sepals sometimes petaloid); imbricate. Corolla when present, 6–9; 1–3 whorled; polypetalous (the petals larger than the sepals); imbricate.
Androecium 6–9, or 12–18. Androecial members free of the perianth; free of one another. Androecium exclusively of fertile stamens. Stamens 6–9, or 12–18; isomerous with the perianth, or diplostemonous. Anthers dehiscing via longitudinal slits (Podophyllum), or dehiscing by longitudinal valves (one- or two-valved, opening from the base upwards); extrorse (usually), or introrse (rarely Dysosma); tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with one middle layer, or initially with more than one middle layer (1 or 2). Tapetum probably glandular. Pollen shed in aggregates (e.g.Podophyllum emodi), or shed as single grains (usually); when aggregated, in tetrads. Pollen grains aperturate; 3 aperturate, or 6–12 aperturate; colpate (tricolpate in Podophyllum), or rugate (612 rugate, in Ranzania); 2-celled.
Gynoecium ostensibly 1 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium monomerous; ostensibly of one carpel; superior. Carpel apically stigmatic; 50–100 ovuled (usually, many), or 1 ovuled (Achlys). Placentation marginal (adaxial), or basal (Achlys). Stigmas in Podophyllum and Diphylleia, wet type; non-papillate; Group IV type. Ovules ascending; anatropous; bitegmic; pseudocrassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3 (large); not proliferating. Synergids with filiform apparatus. Endosperm formation nuclear. Endosperm haustoria absent. Embryogeny onagrad.
Fruit fleshy, or non-fleshy. The fruiting carpel dehiscent, or indehiscent; a follicle (opening transversely or obliquely), or baccate (Podophyllum). Seeds endospermic. Endosperm oily. Cotyledons 2. Embryo achlorophyllous (1/1).
Physiology, phytochemistry. Not cyanogenic. Proanthocyanidins absent. Ellagic acid absent (Podophyllum). Sieve-tube plastids S-type.
Geography, cytology. Holarctic. Temperate. North temperate, especially Eastern Asia and Eastern North America.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Ranunculiflorae; Ranunculales. Cronquists Subclass Magnoliidae; Ranunculales. APG 3 core angiosperms; peripheral eudicot; Superorder Ranunculanae; Order Ranunculales (as a synonym of Berberidaceae).
Species 20. Genera 6; Achlys, Diphylleia, Dysosma, Jeffersonia, Ranzania, Podophyllum.
General remarks. Cf. Berberidaceae sensu stricto (q.v.), but more or less differing in the palmately veined leaves and herbaceous (biennial) habit, as well as in records of stems with cortical and medullary vascular bundles and no secondary thickening, colpate or rugate pollen grains, and pseudocrassinucellate ovules.
Illustrations. • Diphylleia (Chittenden). • Jeffersonia (Chittenden). • Stem TS of Podophyllum peltatum, showing scattered vascular bundles (Solereder, 1908).
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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).
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2013. http://delta-intkey.com’.