Papaveraceae Juss.
Including Chelidoniaceae Nak., Chymaceae Dulac, Eschscholziaceae (Ernst) A.C. Smith, Platystemonaceae (Ernst) A.C. Smith
Excluding Fumariaceae, Hypecoaceae, Pteridophyllaceae
Habit and leaf form. Herbs (mostly), or trees to shrubs (a few shrubs or small treelets); laticiferous, or with coloured juice (usually, the juice milky, yellow, or red), or non-laticiferous and without coloured juice (e.g. Eschscholtzia, Platystemon with watery juice). ‘Normal’ plants. Annual, or perennial; with neither basal nor terminal aggregations of leaves. The treelets pachycaul. Mesophytic. Leaves alternate (usually, though the floral leaves are sometimes opposite or whorled), or whorled (ostensibly, in Platystemon); spiral; petiolate to sessile; non-sheathing; simple. Lamina dissected (usually), or entire; usually pinnatifid (lobed or dissected), or much-divided (e.g. bipinnatisect); pinnately veined (mostly), or palmately veined (e.g., Eomecon); cross-venulate. Leaves exstipulate; without a persistent basal meristem.
General anatomy. Plants with laticifers (articulated, anastomosing or not), or without laticifers. The laticifers in leaves, in stems, in roots, in flowers, and in the fruits.
Leaf anatomy. Hydathodes present (occasionally), or absent. Stomata anomocytic. Hairs present, or absent; eglandular; unicellular, or multicellular. Complex hairs absent.
Minor leaf veins without phloem transfer cells (Mecanopsis).
Stem anatomy. Nodes unilacunar, or tri-lacunar. Primary vascular tissue comprising a ring of bundles, or in two or more rings of bundles; centrifugal. Cortical bundles absent. Medullary bundles absent. Secondary thickening absent (commonly), or developing from a conventional cambial ring. Xylem with libriform fibres; with vessels. Vessel end-walls horizontal, or oblique; simple. Wood parenchyma paratracheal (vasicentric to sparse). Sieve-tube plastids S-type.
Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite; not viviparous. Floral nectaries absent. Anemophilous (e.g., Bocconia, Macleaya), or entomophilous (mostly).
Inflorescence, floral, fruit and seed morphology. Flowers solitary (mostly), or aggregated in ‘inflorescences’; in cymes and in racemes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; racemes or dichasia. Flowers medium-sized, or large; calyptrate, or not calyptrate; odourless; regular, or somewhat irregular. The floral irregularity involving the perianth (when manifest). Flowers cyclic; tetracyclic to pentacyclic to polycyclic. Floral receptacle developing an androphore, or developing a gynophore, or with neither androphore nor gynophore. Free hypanthium absent (usually), or present (Platystemon). Hypogynous disk absent.
Perianth with distinct calyx and corolla (usually), or sepaline (the corolla lacking in Macleaya); 6(–10); 1 whorled, or 3 whorled, or 4 whorled; isomerous (nearly always), or anisomerous (Sanguinaria). Calyx 2(–4); 1 whorled; polysepalous, or gamosepalous (sometimes basally connate, sometimes coherent into an operculum); unequal but not bilabiate, or regular (usually rather asymmetrical); basally appendaged (sepals sometimes lobed), or neither appendaged nor spurred; not persistent (caducous); calyptrate, or not calyptrate; imbricate. Corolla 4, or 6, or 8, or 12, or 16; 2 whorled (often 2+2 or 3+3), or 3 whorled; polypetalous; imbricate and crumpled in bud; regular; yellow, or orange, or red, or pink, or blue; not spurred.
Androecium 4–6 (Meconella), or 16–200 (usually ‘many’). Androecial members usually maturing centripetally; free of the perianth; free of one another; 3–15 whorled (generally indefinite in 2- or 3-merous, regularly alternating whorls). Androecium exclusively of fertile stamens. Stamens 4–6 (rarely), or 16–60; isomerous with the perianth (rarely), or diplostemonous to polystemonous. Anthers basifixed; non-versatile; dehiscing via longitudinal slits; tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer, or initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate (usually?), or nonaperturate (e.g., some Mecanopsis species); (2–)3 aperturate, or 4 aperturate, or 6–8 aperturate, or 9(–15) aperturate; colpate (mostly, tricolpate, rarely slightly colporoidate), or foraminate, or rugate; 2-celled.
Gynoecium 2(–100) carpelled (to ‘many’). Carpels isomerous with the perianth, or increased in number relative to the perianth. The pistil 1–20 celled. Gynoecium syncarpous; semicarpous (Platystemon), or eu-syncarpous (usually, the stigmas often connate to form a discoid roof on the ovary); superior. Ovary 1 locular, or 2–20 locular (by intrusion of the placentas). Locules secondarily divided by ‘false septa’ (then spuriously bilocular), or without ‘false septa’. Gynoecium when G2, transverse. Ovary sessile, or stipitate. Gynoecium non-stylate, or stylate. Styles when gynoecium stylate, 1; attenuate from the ovary; apical. Stylar canal present. Stigmas as many as the placentas; dorsal to the carpels, or commissural, or dorsal to the carpels and commissural; often combined into a peltate structure; dry type; papillate; Group II type. Placentation when unilocular parietal (usually), or basal (Bocconia); when plurilocular, axile, or parietal (Romneya). Ovules in the single cavity when unilocular 1 (Bocconia), or 2–100 (usually ‘many’); when plurilocular, 2–50 per locule (few to ‘many’); funicled; horizontal, or ascending; with ventral raphe; collateral, or superposed, or over the carpel surface, or biseriate; arillate, or non-arillate; anatropous, or campylotropous, or amphitropous (seemingly mostly anatropous or subcampylotropous); bitegmic; crassinucellate. Outer integument contributing to the micropyle. 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 nuclear. Embryogeny solanad (or irregular).
Fruit non-fleshy; more or less an aggregate (Platystemon), or not an aggregate; dehiscent (usually), or indehiscent (rarely), or a schizocarp (Platystemon). Mericarps in Platystemon, 2–20(–30). Fruit a capsule (usually), or a silicula, or a siliqua, or a nut (rarely). Capsules poricidal, or septicidal, or valvular (then dehiscence basipetal or acropetal). Fruit elastically dehiscent, or passively dehiscent. Dispersal unit the seed, or the mericarp, or the fruit. Dispersal by explosive xerochastic dehiscence, censer action in windy conditions, or passive fall; commonly involving ants when elaiosomes present; rarely (Arctomecon) the fruits fall and tummble in the wind. Fruit 1–100 seeded (i.e. to ‘many’). Seeds copiously endospermic. Endosperm oily. Seeds small. Embryo rudimentary at the time of seed release (sometimes), or weakly differentiated. Cotyledons 2. Embryo achlorophyllous (7/8). Testa non-operculate; smooth.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Cyanogenic, or not cyanogenic. Cynogenic constituents tyrosine-derived. Alkaloids present (nearly always), or absent. Berberine present (at least in Argemone), or absent. Iridoids not detected. Proanthocyanidins absent. Flavonols present; kaempferol, or quercetin, or kaempferol and quercetin. Ellagic acid absent (6 species, 6 genera). Arbutin absent. Aluminium accumulation not found. C3. C3 physiology recorded directly in Argemone, Macleaya.
Geography, cytology. Holarctic, Paleotropical, Neotropical, Cape, and Australian. Frigid zone to sub-tropical. Mainly North temperate, but also in Iceland, Central America and West Indies, South Africa and Eastern Australia. X = (5-)6, 7, 8, 11, 19.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Ranunculiflorae; Papaverales. Cronquist’s Subclass Magnoliidae; Papaverales. APG (1998) Eudicot; peripheral Eudicot (non-core Eudicots, ‘neither Rosid nor Asterid’); Ranunculales. Species 200. Genera 23; Arctomecon, Argemone, Bocconia, Canbya, Chelidonium, Dendromecon, Dicranostigma, Eomecon, Eschscholzia, Glaucium, Hunnemannia, Hylomecon, Macleaya, Meconella, Mecanopsis, Papaver, Platystemon, Platystigma, Roemeria, Romneya, Sanguinaria, Stylomecon, Stylophorum.
Description improved by Una Smith, July 1998.
Economic uses, etc. Unripe capsules of Papaver somniferum supply commercial opium, and numerous species from Papaver, Meconopsis, Argemone, etc. are cultivated as ornamentals.
Illustrations. • Glaucium, Roemeria, Papaver. • Papaver, Chelidonium. • Technical details (Papaver rhoeas). • Technical details (Glaucium, Mecanopsis). • Technical details (Chelidonium, Eschscholzia, Roemeria).
Quotations
. . . Not poppy, nor mandragora,
Nor all the drowsy
syrups of the world,
Shall ever med’cine thee to that sweet sleep
Which thou owed’st yesterday
(‘Othello’, iii., 3 -
‘owed’st = ‘owned’)
Corn poppies, that in crimson dwell,
Called Head-aches, from their sickly smell
(John Clare, quoted by Ann
Pratt, ‘Wild Flowers’ (1857)
On her cheek an autumn flush,
Deeply ripen’d; - such a blush
In the midst of brown was born,
Like red poppies grown with corn
(Thomas Hood, ‘Ruth’)
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).
