The families of flowering plants
Including Cassuvieae (Cassuviaceae) R.Br., Spodiaceae (Spodiadaceae) Hassk., Spondiaceae (Spondiadaceae) Kunth; excluding Blepharocaryaceae, Pellicieraceae, Pistaciaceae, Podoaceae.
Habit and leaf form. Trees, or shrubs; usually resinous (although it is unclear from the references seen whether the sometimes milky juice recorded in this and related families is resinous or laticiferous). Self supporting, or climbing. Leaves evergreen, or deciduous; nearly always alternate (opposite in Bouea); when alternate, spiral; herbaceous; aromatic (resinous), or without marked odour (?); simple, or compound; when compound, ternate, or pinnate. Lamina pinnately veined. Leaves exstipulate. Lamina margins entire. Domatia occurring in the family (recorded in 8 genera); manifested as pits, or pockets, or hair tufts.
Leaf anatomy. Abaxial epidermis papillose, or not papillose. Stomata mainly confined to one surface, or on both surfaces; where recorded anomocytic. Hairs of diverse forms recorded - unicellular, uniseriate, glandular and eglandular, peltate, stellate, etc. Adaxial hypodermis present, or absent. Lamina with secretory cavities (with canals in the phloem, but not noticeably gland-dotted). Secretory cavities containing resin. The mesophyll containing crystals. The crystals druses, or solitary-prismatic. Main veins embedded. Minor leaf veins without phloem transfer cells (Odina (= Lannea)).
Axial (stem, wood) anatomy. Secretory cavities present (as canals, especially in the primary phloem); with resin (i.e., assuming the sometimes milky juice is not laticiferous). Cork cambium present; usually initially superficial. Nodes tri-lacunar. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow (mostly), or wide, or mixed wide and narrow. The axial xylem with vessels.
The wood ring porous to semi-ring porous (rarely), or diffuse porous (usually). The vessels moderately small, or medium, or large; solitary, or radially paired, or in radial multiples, or clustered, or in tangential arcs. The vessel end-walls simple (usually), or scalariform and simple. The vessels without vestured pits; with spiral thickening, or without spiral thickening. The axial xylem without fibre tracheids; with libriform fibres; at least sometimes including septate fibres, or without septate fibres (?). The fibres without spiral thickening. The parenchyma predominantly paratracheal (often scanty, rarely absent). Included phloem absent. The wood not storied. Tyloses commonly present.
Reproductive type, pollination. Plants hermaphrodite, or monoecious, or dioecious, or gynodioecious, or polygamomonoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in panicles. The ultimate inflorescence units racemose. Flowers regular; typically 5 merous; cyclic; tetracyclic, or pentacyclic. Free hypanthium present (short), or absent. Hypogynous disk present; intrastaminal; annular.
Perianth with distinct calyx and corolla, or sepaline; 3–5, or 6–10; 1 whorled, or 2 whorled; isomerous. Calyx 3–5; 1 whorled; basally gamosepalous. Calyx lobes markedly shorter than the tube to markedly longer than the tube. Calyx regular; imbricate. Corolla when present, 3–5; 1 whorled; polypetalous, or gamopetalous (rarely, basally). Corolla lobes markedly longer than the tube. Corolla imbricate.
Androecium 5–10(–12). Androecial members free of the perianth; all equal, or markedly unequal; free of one another, or coherent; when coherent 1 adelphous (the filaments sometimes basally connate); 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens, or including staminodes. Staminodes when present, 1–9. Stamens (1–)5–10(–12); oppositisepalous. Anthers dorsifixed (mostly), or basifixed (e.g. Spondias); versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with more than one middle layer (usually), or initially with one middle layer (Rhus mysurensis); of the basic type, or of the dicot type. Tapetum glandular. Pollen monosiphonous; shed as single grains. Pollen grains aperturate; (2–)3 aperturate; colporate; 2-celled.
Gynoecium 1–3–5(–6) carpelled. The pistil 1–5 celled. Gynoecium syncarpous; semicarpous (rarely), or synovarious, or synstylovarious; superior (usually), or partly inferior. Ovary 1–5 locular. Styles 1 (usually), or 3–6 (Buchanania with up to five styles from sterile carpels). Stigmas 1–5; wet type; non-papillate; Group IV type. Placentation when unilocular parietal, or basal; when bi- or plurilocular basal. Ovules in the single cavity when unilocular, 1; 1 per locule; pendulous, or ascending; apotropous; with ventral raphe (when erect, the micropyle inferior), or with dorsal raphe (when pendulous, the micropyle superior); non-arillate; anatropous; unitegmic, or bitegmic; crassinucellate. Outer integument contributing to the micropyle, or not contributing to the micropyle. Endothelium not differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids hooked. Hypostase present, or absent. Endosperm formation nuclear.
Fruit fleshy (usually), or non-fleshy (occasionally); when dry indehiscent; a drupe. The drupes with one stone. Seeds non-endospermic. Cotyledons 2. Embryo chlorophyllous (4/4), or achlorophyllous (2/2); curved.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, phytochemistry. C3. C3 physiology recorded directly in Rhus. Anatomy non-C4 type (Mangifera). Sugars transported as sucrose, or as oligosaccharides + sucrose, or as sugar alcohols + oligosaccharides + sucrose (but sucrose always predominating). Not cyanogenic. Alkaloids present, or absent (mostly). Anthraquinones detected (Lannea); polyacetate derived. Arbutin absent. Iridoids not detected. Saponins/sapogenins present (rarely), or absent. Proanthocyanidins present (usually?), or absent (Mangifera); when present, delphinidin, or cyanidin and delphinidin. Flavonols present; kaempferol and quercetin, or quercetin and myricetin, or kaempferol, quercetin, and myricetin. Ellagic acid absent (3 genera, 4 species). Aluminium accumulation not found.
Geography, cytology. Sub-tropical to tropical (mainly). Widespread in the tropics, also Mediterranean, E. Asia, America. X = 7–16.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rutiflorae; Sapindales. Cronquists Subclass Rosidae; Sapindales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Sapindales.
Species 600. Genera about 70; Actinocheita, Anacardium, Androtium, Antrocaryon, Apterokarpos, Astronium, Baronia, Bonetiella, Bouea, Buchanania, Campnosperma, Cardenasiodendron, Choerospondias, Comocladia, Cotinus, Cyrtocarpa, Dracontomelon, Drimycarpus, Ebandoua, Euleria, Euroschinus, Faguetia, Fegimanra, Gluta, Haematostaphis, Haplorhus, Harpephyllum, Heeria, Holigarna, Koordersiodendron, Lannea, Laurophyllus, Lithrea, Loxopterigium, Loxostylis, Mangifera, Mauria, Melanochyla, Metopium, Micronychia, Montagueia, Mosquitoxylum, Nothopegia, Ochoterenaea, Operculicarya, Ozoroa, Pachycormus, Parishia, Pegia, Pentaspadon, Pleiogynium, Poupartia, Protorhus, Pseudoprotorhus, Pseudosmodingium, Pseudospondias, Rhodosphaera, Rhus, Schinopsis, Schinus, Sclerocarya, Semecarpus, Smodingium, Solenocarpus, Sorindeia, Spondias, Swintonia, Tapirira, Thyrsodium, Toxicodendron, Trichoscypha.
General remarks. Blepharocaryaceae, Julianiaceae, Pistaciaceae and Podoaceae (q.v.) are dubiously justifiable as distinct families, with frequent occurrence of monoecism and dioecism complicating foral morphological comparisons.
Economic uses, etc. Including commercially important fruits cashew-nut (Anacardium, and the fleshy peduncle, cashew-apple), mango (Mangifera), Jamaica plum, hog-plum, imbu (Spondias). Resins, oils and lacquers from Toxicodendron.
Illustrations. • Lannea - technical details (Thonner). • Sclerocarya, Odina - technical taxonomic details. • Androtium astylum: Hook. Ic. Pl. 28 (1902). • Rhus: Technical details. • Duvaua longifolia: Bot. Reg. 29 (59), 1843. • Mangifera indica: Bot. Mag. 76 (1850). • Melanochyla tomentosa: Hook. Ic. Pl. 13 (1877–79). • Nothopegia racemosa, as Glycycarpus: Hook. Ic. Pl. 9 (1852). • Gluta curtisii, as Melanorhoea: Hook. Ic. Pl. 16 (1866). • Spondias pinnata (as S. mangifera): R. Wight (1840).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 12th September 2017. delta-intkey.com/angio’.