| | The Families of Angiosperms |
Including Achraceae Roberty, Achradaceae von Vest, Bumeliaceae Barnh.; excluding Sarcospermataceae.
Habit and leaf form. Trees and shrubs; laticiferous, or with coloured juice (yellow in Chromolucuma, blue in Niemeyera). Mesophytic. Leaves persistent; alternate (usually), or opposite, or whorled; spiral, or distichous; leathery; petiolate; non-sheathing; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate (rarely), or exstipulate. Stipules sometimes represented by stalked glands. Lamina margins entire. Domatia occurring in the family; manifested as pits.
General anatomy. Plants with laticifers (these articulated). The laticifers in leaves, in stems, and in roots. Plants with ‘crystal sand’, or without ‘crystal sand’.
Leaf anatomy. The leaf lamina dorsiventral, or centric. Stomata mainly confined to one surface (nearly always abaxial only), or on both surfaces (rarely); anomocytic (usually), or paracytic (recorded in only a few species). Hairs present; eglandular and glandular (the latter often secreting resin); mostly or exclusively unicellular. Unicellular hairs branched (usually 2-armed or with one of the arms reduced or absent), or simple (abundant in Delpydora, rarely scalelike). Adaxial hypodermis present (commonly), or absent. The mesophyll with sclerenchymatous idioblasts (commonly), or without sclerenchymatous idioblasts; containing crystals. The crystals druses, or solitary-prismatic (or in the form of crystal sand). Minor leaf veins without phloem transfer cells (Chrysophyllum, Pouteria).
Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar (usually), or unilacunar. Primary vascular tissues in a cylinder, without separate bundles; collateral. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow.
The vessels small to large; commonly solitary, radially paired, in radial multiples, and in tangential arcs. The vessel end-walls simple. The vessels without vestured pits. The axial xylem with tracheids, or without tracheids (?); often with vasicentric tracheids; with fibre tracheids, or without fibre tracheids (mostly); with libriform fibres, or without libriform fibres; including septate fibres (rarely), or without septate fibres. The fibres without spiral thickening. The parenchyma typically apotracheal; wood not storied.
Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when aggregated, in cymes, or in panicles. The ultimate inflorescence units cymose. Inflorescences axillary (sometimes on old stems); cymose bunches. Flowers bracteolate; small (often), or medium-sized; regular (usually), or somewhat irregular to very irregular; cyclic; tetracyclic to polycyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 6–16(–20); 2 whorled, or 3 whorled; isomerous. Calyx 4, or 5, or 6, or 8; 1 whorled (then 5), or 2 whorled (then 2+2, 3+3 or 4+4); polysepalous; when one whorled, imbricate. Corolla 3–6, or 8, or 10; 1 whorled, or 2 whorled (and sometimes ostensibly 2-whorled, through the lobes of the single whorl bearing dorsal appendages like themselves); appendiculate (with dorsal appendages on the lobes), or not appendiculate; gamopetalous; imbricate.
Androecium 4–15. Androecial members adnate (to the corolla); free of one another; 1–3 whorled. Androecium exclusively of fertile stamens to including staminodes (the outer, antesepalous whorl when present often staminodal). Staminodes 2, or 3, or 4, or 5; when present, external to the fertile stamens; petaloid, or non-petaloid. Stamens 4–15; isomerous with the perianth, or diplostemonous, or triplostemonous; alternisepalous, or oppositisepalous; opposite the corolla members, or both alternating with and opposite the corolla members. Anthers dehiscing via longitudinal slits; commonly extrorse; tetrasporangiate. Pollen grains aperturate; 3–4(–6) aperturate; colporate; 2-celled (Calocarpum), or 3-celled (Bumelia, Dipholis).
Gynoecium (2–)4–14(–30) carpelled. Carpels isomerous with the perianth, or increased in number relative to the perianth (commonly double the number of one staminal whorl). The pistil (2–)4–14(–30) celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary (2–)4–14(–30) locular. Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stigmas 1; dry type; papillate; Group II type. Placentation axile, or axile to basal. Ovules 1 per locule; ascending; hemianatropous to anatropous; unitegmic; tenuinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells not formed (the three nuclei soon degenerating). Synergids hooked. Endosperm formation nuclear.
Fruit fleshy; indehiscent; a berry (although the flesh is “sometimes sclerenchymatous near the outside”). Seeds endospermic, or non-endospermic. Endosperm oily. Seeds with amyloid, or without amyloid. Embryo well differentiated. Cotyledons 2 (large, thin, flat). Embryo achlorophyllous (4/4).
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, phytochemistry. Sugars transported as sucrose (in 5 genera). Cyanogenic, or not cyanogenic. Cynogenic constituents phenylalanine-derived. Alkaloids present, or absent. Iridoids not detected. Saponins/sapogenins present, or absent. Proanthocyanidins present, or absent (Pouteria); when present, delphinidin, or cyanidin and delphinidin. Flavonols present; kaempferol, or quercetin and myricetin, or kaempferol, quercetin, and myricetin. Ellagic acid absent (5 genera, 5 species). Aluminium accumulation not found.
Geography, cytology. Tropical. Pantropical. X = 7, 9–13.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Primuliflorae; Ebenales. Cronquist’s Subclass Dilleniidae; Ebenales. APG III core angiosperms; core eudicot; Superorder Asteranae. APG IV Order Ericales.
Species 800. Genera about 55 (35–75, with problems over generic definition); Achras (= Manilkara), Argania, Aubregrinia, Aulandra, Autranella, Baillonella, Breviea, Bumelia, Burckella, Butyrospermum, Calocarpum, Capurodendron, Chromolucuma, Chrysophyllum, Delpydora, Diploknema, Dipholis, Diploon, Eberhardtia, Ecclinusa, Elaeoluma, Englerophytum, Faucherea, Gluema, Inhambanella, Isonandra, Labourdonnaisia, Labramia, Lecomtedoxa, Leptostylis, Letestua, Madhuca, Manilkara, Micropholis, Mimusops, Neohemsleya, Neolemonniera, Nesoluma, Niemeyera, Northia, Omphalocarpum, Palaquium, Payena, Pichonia, Planchonella, Pouteria, Pradosia, Pycnandra, Sarcaulus, Sideroxylon, Tieghemella, Tridesmostemon, Tsebona, Vitellaria, Vitellariopsis, Xantolis.
Economic uses, etc. Edible fruits from Achras sapota (sapodilla, sapota, marmalade plum, chiku), Chrysophyllum cainito (star-apple), Pouteria (abiu, canistel, eggfruit), Sideroxylon australe (Australian native plum); gutta-percha from the latex of Palaquium gutta.
Illustrations. • Le Maout and Decaisne: Achras = Manilkara, Argania, Sideroxylon. • Le Maout and Decaisne: Monotheca. • Achras (= Manilkara), floral details: Bot. Mag. 58 (1831). • Achras (= Manilkara), fruit details: Bot. Mag. 58 (1831). • Chrysophyllym imperiale: Bot. Mag. 111 (1885). • Chrysophyllum oliviforme subsp. oliviforme (as C. monopyrenum): Bot Mag. 61 (1834). • Mimusops coriacea (as M. dissecta): Bot. Mag. 59 (1832). • Mimusops kummel: Thonner. • Madhuca longifolia: R. Wight 2 (1850, as Bassia). • Madhuca neriifolia, as Bassia: Trimen, Ill. Fl. Ceylon (1895). • Northia seychellana: Hook. Ic. Pl. 15 (1884). • Palaquium gutta: Köhler’s Medizinal-Pflanzen 3 (1898). • Payena leerii: Köhler’s Medizinal-Pflanzen 3 (1898). • Pouteria multiflora, as Lucuma: Hook. Ic. Pl. 25 (1896). • Pouteria gardneriana, as P. suavis: Hook. Ic. Pl. 29 (1907). • Pouteria guianensis (as Lucuma hartii): Hook. Ic. Pl. 26 (1898). • Sideroxylon lycioides (as Bumelia): Baillon, Histoire des Plantes 11 (1892). • Sideroxylon mitis var. mitis: Bot. Mag. 43 (1858) as Sideroxylon mite.
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: 25th April 2024. delta-intkey.com’.
