Papaveraceae Juss.

Edwards, S.L. (2014). Neotropical Papaveraceae.

Morphology

Description

Habit:  annual , biennial or perennial herbs or pachycaulous treelets (Bocconia L.) with orange, yellow, white or watery latex . Leaves usually alternate , occasionally subopposite or whorled (in Fumarioideae), petiolate to sessile , simple , entire to ternately divided ; stipules absent. Inflorescences terminal or axillary , paniculate or racemose, or flowers solitary. Flowers bisexual , actinomorphic (in Papaveroideae) or zygomorphic (in Fumarioideae), often nodding when in bud , sometimes erect ; sepals 2-3, caducous , herbaceous or small, petaloid (in Fumarioideae); petals 4-6; ovary superior , syncarpous, two to many carpellate; stamens usually many, free , arising centripetally or 2 (in Fumarioideae). Fruits one- (Bocconia) to usually many-seeded capsules or nuts (Fumaria L.). Seeds usually small.

Distribution

Distribution in the Neotropics

Worldwide the Papaveraceae comprise 41 genera and ca. 700 species. Of these ca. 13 genera and ca. 58 species occur in the Neotropics. Representation of genera:

• Argemone L.: (ca. 25 species) mostly from North America and North Mexico, but also with a small centre of diversity in Chile with ca. 7 species, 4 of which do not occur in Mexico. Argemone mexicana L. is the most widespread species and has been recorded in most Central and South America countries and the Caribbean, except Colombia and the Galapagos Islands.
• Bocconia L.: (7 species) along the west coast of South America from Northern Mexico to Northern Argentina, and in the West Indies.
• Chelidonium L.: (1 species) Chelidonium majus L. introduced from Eurasia, only recorded from Peru and Argentina.
• Corydalis DC.: (1 species) Corydalis aurea Willd. North America extending south into Mexico.
• Dendromecon Benth.: (1 species) Dendromecon rigida Benth. in Western North America and Baja California in Mexico.
• Eschscholzia Cham. (3 species) mostly North American but 3 species extend south into Mexico. Eschscholzia californica Cham. also occurs in Ecuador, Argentina and Chile.
• Fumaria L.: (6 species) mostly weeds of Mediterranean origin, extending from Mexico along western Central and South America to Argentina and Chile.
• Glaucium Mill.: (2 species) in Argentina, introduced from Atlantic Europe and Central Asia.
• Hunnemannia Sweet: (2 species) Hunnemannia fumariifolia Sweet is endemic to Mexico and H. hintoniorum Sweet is southern North America, Mexico and Honduras.
• Papaver L. (7 species) mostly from the Northern hemisphere, but several species are widely cultivated.
• Platystemon Benth. (1 species) Platystemon californicus Benth. mainly in North America but extends into adjacent Baja California, Mexico.
• Romneya Harv. (1 species) Romneya trichocalyx Eastw. from adjacent California and Baja California, Mexico.
• Stylomecon G. Taylor (1 species) Stylomecon heterophylla (Benth.) G. Taylor from adjacent California and Baja California, Mexico.

Diagnostic

Distinguishing characters (always present)

• Herbs, shrubs or pachycaulous trees.
• Plants with exudate.
• Leaves usually alternate or whorled, simple.
• Fruits usually dehiscent capsules or nuts with parietal placentation.

Key differences from similar families

• Berberidaceae: Shrubs or rarely trees, often spiny, often with yellow wood, without latex. Flowers a trimerous, usually less than 10 mm wide, perianth 3-6 whorls; bracteoles caducous, 3, scale-like; stamens 6, nectries at base of stamens; ovary 3-carpellate, 1 locule. Fruit a berry, 1-10 seeds.
• Lamiaceae: (some superficial similarities to Fumarioideae) cross-section of stem is often quadrangular. Leaves usually opposite, decussate, sometimes whorled. Flowers zygomorphic, usually tubular and 5-merous; corolla usually bilabiate; stamens 2-4. Fruits of 1-4 nutlets.
• Ranunculaceae: Herbs or climbers, without latex. Sepals 5-8+, not caducous, often petal-like; petals 0-50, clawed; gynoecium apocarpous. Fruits achenes or follicles, usually aggregated into a head, less frequently berries.

Useful tips for generic identification

Key to the Neotropical genera of the Papaveraveae A combination of keys in Kadereit (1993) and Lidén (1993), modified to include only the genera that occur in the Neotropics.

1. Flowers zygomorphic. Sepals 2, petaloid... 2
1. Flowers actinomorphic. Sepals 2-3 usually green and herbaceous... 3

2. Fruit a single-seeded nut. Seeds brown. Style caducous. Stigma two big papillae ... Fumaria
2. Fruit a many-seeded dehiscent capsule. Seeds black. Style persistent. Stigmas usually flattened with marginal papillae ... Corydalis

3. Corolla absent. Fruit a single-seeded capsule. Usually pachycaulous trees, sometimes shrubs ... Bocconia
3. Corolla present. Fruit a many-seeded dehiscent capsule. Usually herbs, sometimes shrubs ... 4

4. Ovary bicarpellate ... 5
4. Ovary with 3-25 carpels ... 9

5. Mature capsules with 10 conspicuous longitudinal veins. Fruit dehisces explosively. Stigmas sessile. Hairs unicellular, when present ... 6
5. Mature capsules without 10 conspicuous longitudinal veins. Fruit dehiscence never explosive. Stigmas on a short style. Hairs multicellular, when present ... 8

6. Evergreen woody shrubs. Leaves undivided ... Dendromecon
6. Annual or perennial herbs. Leaves many-lobed... 7

7. Sepals united ... Eschscholzia
7. Sepals free... Hunnemannia

8. Inflorescence an umbel, flowers supported by small entire bracts ... Chelidonium
8. Flowers solitary ... Glaucium

9. Leaves linear, margin entire. Fruits breaking into 1-seeded mericarps. Carpel tips and stigmas free... Platystemon
9. Leaves pinnately incised or divided. Fruits opening by basipetal valves. Carpel tips united, stigmas of neighbouring carpels confluent ... 10

10. Style distinct. Capsular fruit, the base of the style flattened into a disk at the top of the capsule... Stylomecon
10. Stigmas sessile or on a short style. Capsular fruit without a style or if they have a style, then not flattening into a disk ... 11

11. Sepals with distinct stiff, apical horns. Seeds orbicular. Stigmas usually on a short style... Argemone
11. Sepals without distinct stiff, apical horns. Seeds irregularly angular to ellipsoid or reniform. Stigmas sessile... 12

12. Stigmas linear, fused into a flat to conical disc, sometimes deeply furrowed between the individual stigma s. Ovary clavate to globose. Fruits opening by basipetal pores or short valves below the disc. Seeds reniform... Papaver
12. Stigmas not fused into a disc. Placentae fused into a central column. Ovary ovoid. Fruits opening by basipetal valves up to ½ the length of the fruit.  Seeds irregularly angular or ellipsoid... Romneya

Notable genera and distinguishing features

• Argemone: Sepals with stiff conspicuous apical horns. (Common name 'Horned Poppy').
• Bocconia: Pachycaulous trees 2-6 m tall. Calyx of 2 sepals, corolla absent. Fruit single-seeded.
• Eschscholzia: Sepals fused. Gynoecium bicarpellate. Fruits with 10 conspicuous longitudinal ribs, dehiscing explosively.
• Fumaria: Glabrous. Flowers zygomorphic. Stigma with two large papillae. Fruit a single-seeded nut.
• Hunnemannia: Sepals free. Gynoecium bicarpellate. Fruits with 10 conspicuous longitudinal ribs, dehiscing explosively.
• Papaver: Stigmas sessile, linear, arranged into a conical or flat disc. Fruit a capsule dehiscing from pores or short valves just below the stigmatic disc.

General Description

General notes

• The exudates of Papaver somniferum L. and P. bracteatum Lindl. to a lesser extent, are used to make pharmaceuticals such as codeine, opium, morphine and heroine.
• Many other species of Papaveraceae are used in herbal medicine and considered cure alls, treating wide ranging ailments from removing warts to making sedatives, expectorants or purgatives.
• The latex of both Argemone and Bocconia can be used as dyes.
• Papaveraceae are widely cultivated as ornamentals.

Status

• Papaveraceae is mainly a northern temperate family. Some species such as Eschscholzia californica Cham. (Californian Poppy) have been introduced as ornamentals to many areas of the Neotropics. However some genera such as Hunnemannia and Argemone are native. Hunnemannia has one species endemic to eastern Mexico and the other with a slightly wider distribution spreading into North America and south into Honduras.

Notes on delimitation

• In the APG III classification system (Stevens, 2001 onwards) the three families Papaveraceae, Fumariaceae and Pteridophyllaceae (monotypic and endemic to Japan) that used to comprise the order Papaverales (Cronquist 1981; Dahlgren 1989) are now all included within Papaveraceae.  Additionally, in the APG III system Papaverales are not considered to be an order, and the Papaveraceae are placed in the order Ranunculales (Steven 2001 onwards).

Number of genera

• 41 genera (see Distribution in the Neotropics above).

Literature

Important literature

Grey-Wilson, C. 2000. Poppies: The Poppy Family in the Wild and in Cultivation. B.T. Batsford, London.

Kadereit, J.W. 1993. Papaveraceae. In: Kubitzki, K., Rohwer, J.G. & Bittrich, V. (eds.). The Families and Genera of Vascular plants vol. II, pp. 494-506. Springer-Verlag, Berlin.

Lidén, M. 1993. Fumariaceae. In: Kubitzki, K., Rohwer, J.G. & Bittrich, V. (eds.). The Families and Genera of Vascular plants vol. II, pp. 310-318. Springer-Verlag, Berlin.

Lidén, M. 1995. Papaveraceae. In: G. Harling & L. Anderson (eds) Flora of Ecuador 69. 1-13. Department of Plant and Environmental Sciences, University of Gothenburg.

Stein, B.A. 2001. Papaveraceae. In: Stevens, W.D., Ulloa Ulloa, C., Pool, A., Montiel, O.M. (eds.). Flora de Nicaragua vol. 85(III), pp. 1911-1913.Missouri Botanical Garden Press.

Stevens, P. F. 2001 onwards. Angiosperm Phylogeny Website. Version 12, July 2012 [and more or less continuously updated since]. http://www.mobot.org/MOBOT/research/APweb/.

Thornton-Wood, S.P. 2011 Papaveraceae. Flora Mesoamericana, vol. 2(1). http://www.tropicos.org/docs/meso/papaveraceae.pdf

Papaveraceae, G. L. Lucas (East African Herbarium). Flora of Tropical East Africa. 1962

Morphology General Habit

Annual, biennial or perennial herbs, rarely shrubs, and only 1 tree genus (Bocconia L.), with white, yellow or orange coloured latex

Morphology Leaves

Leaves alternate or rarely whorled, exstipulate, entire to much divided (palmately, pinnately etc.)

Morphology Reproductive morphology Flowers

Flowers usually solitary, conspicuous and large, bisexual, regular, hypogynous

Morphology Reproductive morphology Flowers Calyx

Sepals 2–3, imbricate, usually free or calyptrate, caducous

Morphology Reproductive morphology Flowers Corolla

Petals (4–)6(–12), more rarely absent, imbricate, arranged in l–2(–3) whorls, crumpled in bud

Morphology Reproductive morphology Flowers Androecium

Stamens free, usually numerous, spirally arranged, rarely 4 and cyclic ; anthers 2-celled with longitudinal dehiscence

Morphology Reproductive morphology Flowers Gynoecium

Stigmas opposite or alternate with placentas Ovary superior, usually unilocular, more rarely with 2 to several locules ; ovules numerous ; placentation parietal

Morphology Reproductive morphology Fruits

Fruit usually a capsule dehiscing by valves or pores, rarely indehiscent

Morphology Reproductive morphology Seeds

Seeds small, numerous, with minute embryo and copious, usually oily, endosperm

Papaveraceae, A. W. Exell. Flora Zambesiaca 1:1. 1960

Morphology General Habit

Annual, biennial or perennial herbs (rarely shrubby), usually with white or yellowish latex, with alternate, exstipulate leaves

Morphology Reproductive morphology Flowers

Flowers actinomorphic, bisexual, usually hypogynous

Morphology Reproductive morphology Flowers Calyx

Sepals 2–3, imbricate, free or calyptrate, caducous

Morphology Reproductive morphology Flowers Corolla

Petals 4–6 (12) free, imbricate, fugacious

Morphology Reproductive morphology Flowers Androecium

Stamens usually numerous

Morphology Reproductive morphology Flowers Gynoecium

Ovary syncarpous, 1-locular with parietal placentas (rarely multilocular or spuriously 2-locular) and numerous ovules

Morphology Reproductive morphology Fruits

Fruit usually a capsule dehiscing by valves or pores

Morphology Reproductive morphology Seeds

Seeds small, numerous; endosperm oily

Fumariaceae, A. W. Exell. Flora Zambesiaca 1:1. 1960

Morphology General Habit

Herbs, sometimes climbing, with alternate or radical, exstipulate, usually finely divided leaves

Morphology Reproductive morphology Flowers

Flowers in racemes or spikes, rarely solitary, usually zygomorphic, bisexual, hypogynous

Morphology Reproductive morphology Flowers Calyx

Sepals 2 (rarely 0), caducous

Morphology Reproductive morphology Flowers Corolla

Petals 4 (6 or more), one or both of the outer ones spurred or saccate, inner ones often cohering at the apex

Morphology Reproductive morphology Flowers Androecium

Stamens 6, perhaps to be regarded as 2 tripartite elements, the central branch of each bearing a 2-thecous anther and each lateral branch a 1-thecous anther

Morphology Reproductive morphology Flowers Gynoecium

Ovary 1-locular, usually with 2 parietal placentas, each with 1–? anatropous ovules

Morphology Reproductive morphology Fruits

Fruit a capsule or nutlet

Morphology Reproductive morphology Seeds

Seeds with copious endosperm

Fumariaceae, G. L Lucas (East African Herbarium). Flora of Tropical East Africa. 1962

Morphology General Habit

Annual or perennial herbs, erect, straggling or climbing ; sap watery

Morphology Leaves

Leaves radical or alternate or more rarely subopposite, usually much dissected, sometimes ending in a branched tendril

Morphology Leaves Stipules

Stipules absent

Morphology Reproductive morphology Flowers

Flowers either in terminal or leaf-opposed racemes, sometimes spicate, rarely solitary, bisexual, usually irregular

Morphology Reproductive morphology Flowers Calyx

Sepals 2, small, often caducous

Morphology Reproductive morphology Flowers Corolla

Petals 4(–6 or more), if former then imbricate in 2 pairs and often connate at base, with 1 or both the outer pair spurred ; inner pair often united at their apex

Morphology Reproductive morphology Flowers Androecium

Stamens either 4 free and opposite the petals, or 6 united into two groups of 3 by wing-like appendages of the filament to give a thin acuminate membrane surmounted by the 3 anthers

Morphology Reproductive morphology Flowers Gynoecium

Ovules 1-many Ovary unilocular, superior, with 2 parietal placentas ; style filiform ; stigma lobed or entire

Morphology Reproductive morphology Fruits

Fruit a nutlet or capsule

Morphology Reproductive morphology Seeds

Seeds 1–many