Euphorbiaceae Juss.
Including Acalypheae (Acalyphaceae) J.G. Agardh, Bertyaceae J.G. Agardh, Columellaceae Dulac (p.p.), Crotonaceae J.G. Agardh, Hippomaneae (Hippomanaceae) J.G. Agardh, Micrantheae (Micrantheaceae) J.G. Agardh, Oldfieldiaceae auctt., Phyllantheae (Phyllanthaceae) J.G. Agardh, Putranjiveae (Putranjivaceae) Endl., Porantheraceae (Pax) Hurusawa, Pseudanthaceae Endl., Ricinaceae Barkley, Ricinocarpaceae (Pax) Hurusawa, Scepaceae Lindl., Tithymaloideae (Tithymalaceae) Vent., Treviaceae Bullock, Trewiaceae Lindl.
Excluding Androstachydaceae, Bischofiaceae, Hymenocardiaceae, Peraceae, Picrodendraceae, Stilaginaceae, Uapacaceae
Habit and leaf form. Trees, or ‘arborescent’, or shrubs, or herbs, or lianas; laticiferous, or non-laticiferous and without coloured juice (e.g. Phyllanthoideae), or with coloured juice (rarely). ‘Normal’ plants, or switch-plants; often with the principal photosynthesizing function transferred to stems, or phyllodineous, or ‘cactoid’ (often). Leaves well developed, or much reduced. Plants succulent, or non-succulent. Self supporting, or climbing. Mesophytic, or xerophytic. Leaves minute to large; alternate (usually), or opposite to whorled (rarely); spiral, or distichous; ‘herbaceous’, or leathery, or fleshy, or membranous, or modified into spines; petiolate to sessile; non-sheathing; gland-dotted, or not gland-dotted; simple (usually), or compound; not peltate; when compound, palmate. Lamina entire; pinnately veined, or palmately veined. Leaves stipulate (nearly always, but the stipules sometimes reduced to branched hairlike structures, or to glands). Stipules scaly, or leafy, or spiny, or represented by glands; caducous, or persistent. Leaves without a persistent basal meristem. Domatia recorded (from 7 genera); represented by pits, or pockets, or hair tufts (rarely).
General anatomy. Plants with laticifers (commonly, articulated or non-articulated), or without laticifers (absent notably from the Phyllanthoideae).
Leaf anatomy. Mucilaginous epidermis present, or absent. Stomata mainly confined to one surface, or on both surfaces; anomocytic, or anisocytic, or paracytic. Urticating hairs present (in a few lianes), or absent.
Lamina dorsiventral, or isobilateral, or centric; without secretory cavities. The mesophyll with sclerencymatous idioblasts, or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (Euphorbia).
Stem anatomy. Cork cambium present; initially deep-seated (rarely), or superficial. Nodes tri-lacunar, or unilacunar. Primary vascular tissue bicollateral, or centrifugal. Cortical bundles present (occasionally), or absent. Medullary bundles present (occasionally), or absent. Internal phloem present (occasionally), or absent. Secondary thickening developing from a conventional cambial ring (mostly, even in lianes), or anomalous; from a single cambial ring. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones (very rarely. e.g. in Bridelia), or not stratified. ‘Included’ phloem present (occasionally, e.g. Dalechampia), or absent. Xylem with libriform fibres. Vessel end-walls scalariform, or simple (usually). Vessels with vestured pits (rarely), or without vestured pits. Wood parenchyma apotracheal, or paratracheal (or very sparse, or absent).
Reproductive type, pollination. Plants monoecious, or dioecious, or hermaphrodite (very rarely: species of Drypetes, Aporosa). Entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. The terminal inflorescence unit nearly always cymose (commonly the first branching racemose, with all the subsequent branching cymose). Inflorescences terminal, or axillary; with involucral bracts, or without involucral bracts; pseudanthial, or not pseudanthial. Flowers bracteate, or ebracteate (?); minute, or small, or medium-sized; regular. Free hypanthium absent. Hypogynous disk present (commonly), or absent; of separate members, or annular.
Perianth sepaline, or vestigial, or absent, or petaline (occasionally); when present, (3–)5–6(–12); free, or joined; 1 whorled (usually), or 2 whorled (sometimes — e.g. Jatropha); when two-whorled, isomerous. Calyx 5; polysepalous, or gamosepalous; regular. Corolla when present, 5; polypetalous; regular.
Androecium 1–1000 (i.e. to ‘many’). Androecial members branched (e.g. Ricinus), or unbranched; free of the perianth; free of one another, or coherent (may be free or united in a variety of ways). Androecium exclusively of fertile stamens. Stamens 1–1000; reduced in number relative to the adjacent perianth to polystemonous; erect in bud, or inflexed in bud. Anthers dehiscing via longitudinal slits, or dehiscing via pores (rarely with apical pores); extrorse, or introrse; bilocular to four locular; bisporangiate, or tetrasporangiate. Endothecium developing fibrous thickenings. 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; of the ‘dicot’ type, or of the ‘monocot’ type. Tapetum amoeboid, or glandular. Pollen grains aperturate, or nonaperturate (rarely); 3 aperturate (commonly), or 4–30 aperturate (?); colpate, or colporate, or foraminate, or rugate; 2-celled, or 3-celled.
Gynoecium (2–)3 carpelled, or 4–30 carpelled (rarely). The pistil (2–)3 celled, or 4–30 celled (rarely). Gynoecium syncarpous; synovarious, or synstylovarious; superior. Ovary (2–)3 locular, or 4–30 locular (rarely). Styles 3 (usually), or 6(–12) (or more); free, or partially joined (to almost completely joined, in the Phyllantheae); apical. Stigmas 3 (usually), or 6(–12) (or more); dry type; papillate, or non-papillate; Group II type. Placentation axile, or apical. Ovules 1 per locule, or 2 per locule; pendulous; mostly epitropous; with ventral raphe (usually), or with dorsal raphe; when two, collateral; arillate (often carunculate, the caruncle often covering the micropyle, the caruncle often covering the micropyle), or non-arillate; orthotropous, or anatropous, or hemianatropous; bitegmic; crassinucellate. Outer integument usually contributing to the micropyle. Embryo-sac development Polygonum-type, or Allium-type, or Drusa-type, or Fritillaria-type, or Penaea-type. Antipodal cells formed; initially 3; proliferating (to 5 cells, in Jatropha), or not proliferating. Synergids pear-shaped, or hooked (rarely with filiform apparatus). Hypostase present. Endosperm formation nuclear. Embryogeny onagrad (usually), or solanad, or piperad.
Fruit non-fleshy (usually), or fleshy; dehiscent, or indehiscent, or a schizocarp (usually). Mericarps when schizocarpic, (2–)3 (usually, usually dehiscent), or 4–30 (?). Fruit when non-schizocarpic, a capsule, or a drupe; elastically dehiscent (schizocarpic capsules often splitting elastically), or passively dehiscent. Seeds endospermic (nearly always). Endosperm oily. Cotyledons 2 (usually wider than the radicle); flat, or folded. Embryo chlorophyllous (4/6), or achlorophyllous (8/10 — Euphorbia being variable); straight, or curved.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Mustard-oils present (Drypetes, Putranjiva), or absent. Cyanogenic, or not cyanogenic. Cynogenic constituents tyrosine-derived, or phenylalanine-derived (?), or of Hegnauer’s ‘Group C’. Alkaloids present (commonly), or absent. Iridoids not detected. Arthroquinones detected (Clutia); polyacetate derived. Proanthocyanidins present (rarely), or absent; when present, cyanidin and delphinidin (in one Phyllanthus species). Flavonols present, or absent; kaempferol, or kaempferol and quercetin. Ellagic acid present (4 species, 3 genera), or absent (8 species, 5 genera). Arbutin absent. Saponins/sapogenins present (rarely), or absent. Aluminium accumulation demonstrated (but in relatively few genera), or not found. Sugars transported as sucrose (e.g. in Aleurites, Sapium), or as sugar alcohols + oligosaccharides + sucrose (e.g. Phyllanthus, Ricinus). Inulin recorded (Aleurites, Gibbs 1974). C3, C4, and CAM. C3 physiology recorded directly in Argythamnia, Euphorbia, Phyllanthus, Ricinus. C4 physiology recorded directly in Chamaesyce, Euphorbia. CAM recorded directly in Euphorbia, Monadenium, Pedilanthus, Synadenium. Anatomy C4 type (Euphorbia), or non-C4 type (Acalypha, Dalechampia, Croton, Euphorbia, Hevea, Jatropha, Manihot, Meineckia, Micrococca, Phyllanthus, Ricinus, Tragia, Tragiella).
Geography, cytology. Temperate, sub-tropical, and tropical. Cosmopolitan, except Arctic. X = 6–14 (or more).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Malviflorae; Euphorbiales. Cronquist’s Subclass Rosidae; Euphorbiales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid I; Malpighiales. Species 5000. Genera about 300; Acalypha, Acidocroton, Acidoton, Actephila, Adelia, Adenochlaena, Adenocline, Adenopeltis, Adenophaedra, Adriana, Aerisilvaea, Afrotrewia, Agrostistachys, Alchornea, Alchorneopsis, Aleurites, Algernonia, Alphandia, Amanoa, Amperea, Amyrea, Andrachne, Angostyles, Annesijoa, Anomalocalyx, Anthostema, Aparisthium, Apodiscus, Aporusa, Argomuellera, Argythamnia, Aristogeitonia, Ashtonia, Astrocasia, Astrococcus, Austrobuxus, Avellanita, Baccaurea, Baliospermum, Baloghia, Benoistia, Bernardia, Bertya, Beyeria, Blachia, Blotia, Blumeodendron, Bocquillonia, Bonania, Borneodendron, Bossera, Botryophora, Breynia, Bridelia, Calycopeplus, Canaca, Caperonia, Caryodendron, Casabitoa, Calvacoa, Celaenodendron, Celianella, Cephalocroton, Cephalomappa, Chaetocarpus, Chascotheca, Cheilosa, Chiropetalum, Chlamydojatropha, Chondrostylis, Chonocentrum, Choriceras, Chrozophora, Cladogelonium, Cladogynos, Claoxylon, Claoxylopsis, Cleidiocarpon, Cleidion, Cleistanthus, Clutia, Cnesmone, Cnidoscolus, Cocconerion, Codiaeum, Colliguaja, Conceveiba, Cordemoya, Croizatia, Croton, Crotonogyne, Crotonogynopsis, Crotonopsis, Ctenomeria, Cubanthus, Cyrtogonone, Cyttaranthus, Dalechampia, Dalembertia, Deuteromallotus, Deutzianthus, Dichostemma, Dicoelia, Didymocistus, Dimorphocalyx, Discocarpus, Discoclaoxylon, Dicocleidion, Discoglypremna, Dissiliaria, Ditaxis, Ditta, Dodecastigma, Domohinea, Doryxylon, Droceloncia, Drypetes, Duvigneaudia, Dysopsis, Elaeophorbia, Elateriospermum, Eleutherostigma, Endadenium, Endospermum, Enriquebeltrania, Epiprinus, Eremocarpus, Erismanthus, Erythrococca, Euphorbia, Excoecaria, Fahrenheitia, Flueggea, Fontainea, Garcia, Gavarretia, Givotia, Glochidion, Glycydendron, Glyphostylus, Grimmeodendron, Grossera, Gymnanthes, Haematostemon, Hamilcoa, Hevea, Heywoodia, Hippomane, Homonoia, Hura, Hyaenanche, Hieronima, Hylandia, Jablonskia, Jatropha, Joannesia, Kairothamnus, Keayodendron, Klaineanthus, Koilodepas, Lachnostylis, Lasiococca, Lasiocroton, Lautembergia, Leeuwenbergia, Leidesia, Leptonema, Leptopus, Leucocroton, Lingelsheimia, Lobanilia, Loerzingia, Longetia, Mabea, Macaranga, Maesobotrya, Mallotus, Manihot, Manihotoides, Manniophyton, Maprounea, Mareya, Mareyopsis, Margaritaria, Martretia, Megistostigma, Meineckia, Melanolepis, Mercurialis, Micrandra, Micrandropsis, Micrantheum, Micrococca, Mildbraedia, Mischodon, Moacroton, Monadenium, Monotaxis, Moultonianthus, Myladenia, Myricanthe, Nealchornea, Necepsia, Neoboutonia, Neoguillauminia, Neoholstia, Neoroepera, Neoscortechinia, Neotrewia, Octospermum, Oldfieldia, Oligoceras, Omalanthus, Omphalea, Omphellantha, Ophthalmoblapton, Oreoporanthera, Ostodes, Pachystroma, Pachystylidium, Pantadenia, Paradrypetes, Paranecepsia, Parapantadenia, Parodiodendron, Pausandra, Pedilanthus, Pentabrachion, Petalodiscus, Petalostigma, Philyra, Phyllanoa, Phyllanthus, Pimelodendron, Piranhea, Plagiostyles, Platygyna, Plukenetia, Podadenia, Podocalyx, Pogonophora, Poilaniella, Polyandra, Poranthera, Protomegabaria, Pseudagrostistachys, Pseudanthus, Pseudocroton, Pseudolachnostylis, Pterococcus, Ptychopyxis, Putranjiva, Pycnocoma, Reutealis, Reverchonia, Richeria, Richeriella, Ricinocarpus, Ricinodendron, Ricinus, Rockinghamia, Romanoa, Sagotia, Sampantea, Sandwithia, Sapium, Sauropus, Savia, Scagea, Schinziophyton, Sebastiania, Securinega, Seidelia, Senefeldera, Senefelderopsis, Sibangea, Spathiostemon, Speranksia, Sphaerostylis, Sphyranthera, Spirostachys, Spondianthus, Stachyandra, Stachystemon, Stillingia, Strophioblachia, Sumbaviopsis, Suregada, Symphyllia, Synandenium, Syndyophyllum, Tacaruna, Tannodia, Tapoides, Tetracoccus, Tetraplandra, Tetrorchidium, Thecacoris, Thyrsanthera, Tragia, Tragiella, Trevia, Trigonopleura, Trigonostemon, Vaupesia, Vernicia, Vigia, Voatamalo, Wetria, Whyanbeelia, Wielandia, Zimmermannia, Zimmermanniopsis.
Economic uses, etc. Commercial products include rubber (Hevea), tung oil (Aleurites), castor oil (Ricinus), and cassava and tapioca (Manihot). Many ornamentals, especially from Euphorbia (poinsettia, etc.), Codiaeum (croton), Phyllanthus (Otaheite gooseberry).
Illustrations. • Mercurialis, Euphorbia. • Technical details (Phyllanthus). • Technical details (Amperea, Ricinocarpos). • Technical details (Poranthera, Pseudanthus). • Technical details (Phyllanthus, Bridelia, Ricinus, Clutia). • Technical details (Mercurialis, Ditaxis, Baliospermum). • Technical details (Hippomane, Hura, Calycopeplus, Caelebogyne). • Technical details (Euphorbia).
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).
