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. Stomata present; anomocytic.
Lamina dorsiventral. Minor leaf veins without phloem transfer cells (Jeffersonia, Podophyllum).
Stem anatomy. Primary vascular tissue comprising a ring of bundles, or in two or more rings of bundles, or in scattered bundles. Cortical bundles present. Medullary bundles present. Internal phloem absent. Secondary thickening absent (even from the rhizome, according to Tamura 1972). Sieve-tube plastids S-type.
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 (6–12 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 of 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, biochemistry. Not cyanogenic. Proanthocyanidins absent. Ellagic acid absent (Podophyllum).
Geography, cytology. Holarctic. Temperate. North temperate, especially Eastern Asia and Eastern North America.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Ranunculiflorae; Ranunculales. Cronquist’s 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.
• Diphylleia (Chittenden).
• Jeffersonia (Chittenden).