The families of flowering plants
Habit and leaf form. Small trees, or shrubs, or lianas. Climbing (mostly), or self supporting; often stem twiners; Thryallis twining anticlockwise. Mesophytic. Leaves opposite; petiolate, or sessile (rarely); gland-dotted (often), or not gland-dotted; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate, or exstipulate. Stipules interpetiolar, or intrapetiolar; free of one another, or concrescent; often rudimentary, sometimes large. Lamina margins entire. Leaf development not graminaceous. Domatia occurring in the family (Acridocarpus); manifested as hair tufts.
Leaf anatomy. The leaf lamina dorsiventral (usually), or bifacial to centric. Mucilaginous epidermis present, or absent. Stomata mainly confined to one surface (usually), or on both surfaces; paracytic (nearly always), or anomocytic (? - Diacidia). Hairs present (see illustration); eglandular and glandular; mostly unicellular, or multicellular (the glands). Unicellular hairs branched (peculiar, usually with two more or less horizontal arms on a short or long vertical stalk, rarely stellate), or branched and simple (sometimes with bristle hairs as well). Complex hairs usually present (in the form of large, sunken or cushion-shaped glands on the abaxial margins of the lamina and on the petioles). Urticating hairs present (occasionally, modified from 2-celled trichomes in some Malpighia species, from bristles in Camarea), or absent. Lamina without secretory cavities. The mesophyll containing crystals. The crystals druses, or solitary-prismatic, or raphides (rarely). Minor leaf veins without phloem transfer cells (Malpighia).
Axial (stem, wood) anatomy. Secretory cavities absent. Cork cambium present; initially deep-seated (rarely), or initially superficial. Nodes tri-lacunar, or unilacunar. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem present (Dicella, Stigmaphyllon), or absent. Secondary thickening anomalous (frequently: see illustration), or developing from a conventional cambial ring. The anomalous secondary thickening when present, via concentric cambia, or from a single cambial ring (as in Stigmaphyllon, where cambial layers are laid down in xylem parenchyma and ray tissue, generating new bundles of xylem and phloem).
The wood ring porous to semi-ring porous (rarely), or diffuse porous. The vessels in radial multiples (common throughout), or solitary to radially paired, or clustered, or in tangential arcs; with vestured pits. The axial xylem with libriform fibres; including septate fibres (rarely), or without septate fibres. The parenchyma apotracheal, or paratracheal, or apotracheal and paratracheal (predominantly paratracheal in most genera, but predominantly apotracheal in a few including Malpighia). The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones, or not stratified. Included phloem present (commonly), or absent. The wood not storied. Tyloses present (rarely), or absent.
Reproductive type, pollination. Plants hermaphrodite (usually), or polygamomonoecious (rarely). Pollination entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in cymes, in racemes, in umbels, and in panicles. The ultimate inflorescence units cymose. Inflorescences terminal, or axillary; often racemes of cymes. Flowers (two) bracteolate; regular to very irregular; zygomorphic (bilaterally symmetrical). The floral irregularity involving the androecium, or involving the perianth and involving the androecium. Flowers 5 merous; cyclic; pentacyclic. Free hypanthium absent. Hypogynous disk inconspicuous or absent.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous, or gamosepalous (sometimes basally connate); imbricate (often with two large glands at the bases of the outside members). Corolla 5; 1 whorled; polypetalous; imbricate, or contorted. Petals clawed; often fringed.
Androecium 10 (usually), or 5. Androecial members free of the perianth; coherent; 1 adelphous (the filaments basally connate); (1–)2(–3) whorled. Androecium exclusively of fertile stamens, or including staminodes (the members opposite the petals sometimes staminodal or missing). Staminodes 1–5; external to the fertile stamens. Stamens 10 (usually), or 5; isomerous with the perianth to diplostemonous; alternisepalous (usually, the outer whorl opposite the petals), or oppositisepalous (when only the inner whorl present, or the outer whorl staminodal); alternating with the corolla members, or opposite the corolla members, or both alternating with and opposite the corolla members. Anthers dehiscing via longitudinal slits, or dehiscing via pores (rarely, with terminal pores); introrse; tetrasporangiate; appendaged (winged or with the connective prolonged/glandular), or unappendaged. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; 3–5 aperturate, or 4–12 aperturate; porate, or colporate, or foraminate (35 colporate, or oligoforate); 2-celled (in 7 genera).
Gynoecium (2–)3(–5) carpelled (often with one or more carpels aborting). Carpels isomerous with the perianth (usually), or reduced in number relative to the perianth (rarely). The pistil when syncarpous, (2–)3(–5) celled. Gynoecium apocarpous, or syncarpous; eu-apocarpous, or semicarpous, or synovarious; superior. Carpel stylate; when apocarpous, 1 ovuled. Placentation marginal. Ovary when syncarpous, (2–)3(–5) locular. The odd carpel usually obliquely positioned (i.e., when G3). Gynoecium stylate. Styles (2–)3(–5); free; apical. Stigmas dry type; papillate; Group II type. Placentation when syncarpous, axile, or apical. Ovules 1 per locule; pendulous; epitropous; with ventral raphe; hemianatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle, or not contributing to the micropyle. Embryo-sac development Allium-type, or Penaea-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Endosperm formation nuclear. Endosperm haustoria present; chalazal. Embryogeny solanad (or adventive).
Fruit non-fleshy (usually), or fleshy; an aggregate, or not an aggregate. The fruiting carpels of apocarpous forms, coalescing into a secondary syncarp, or not coalescing. The fruiting carpel indehiscent; samaroid, or drupaceous, or nucular. Fruit of syncarpous forms, indehiscent, or a schizocarp. Mericarps when schizocarpic, (2–)3(–5); samaroid (often), or comprising drupelets, or comprising nutlets. Fruit when non-schizocarpic, a drupe, or a nut. Seeds non-endospermic. Cotyledons 2. Embryo straight, or curved (or hooked), or coiled (rarely).
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, phytochemistry. Anatomy non-C4 type (Tristellateia). Sugars transported as sucrose (Byrsonima), or as oligosaccharides + sucrose (Lophanthera). Inulin recorded. Cyanogenic (doubtfully), or not cyanogenic. Alkaloids present, or absent. Iridoids detected (known only from Stigmaphyllon); Route I type (?). Saponins/sapogenins present (rarely), or absent. Proanthocyanidins present, or absent; when present, cyanidin. Flavonols present, or absent; kaempferol, or kaempferol and quercetin. Ellagic acid absent (4 species, 4 genera). Aluminium accumulation not found.
Geography, cytology. Sub-tropical to tropical. Pantropical, concentrated in South America. X = 6, 9–12(+).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rutiflorae; Polygalales. Cronquists Subclass Rosidae; Polygalales. APG III core angiosperms; core eudicot; Superorder Rosanae; fabid. APG IV Order Malpighiales.
Species 1100. Genera about 65; Acmanthera, Acridocarpus, Aspicarpa, Aspidopterys, Banisteriopsis, Barnebya, Blepharandra, Brachylophon, Bunchosia, Burdachia, Byrsonima, Callaeum, Calyptostylis, Camarea, Caucanthus, Clonodia, Coleostachys, Cordobia, Diacidia, Dicella, Digoniopterys, Dinemagonum, Dinemandra, Diplopterys, Echinopterys, Ectopopterys, Flabellaria, Gallardoa, Galphimia, Gaudichaudia, Glandonia, Heladena, Henleophytum, Heteropterys, Hiptage, Hiraea, Janusia, Jubelina, Lasiocarpus, Lophanthera, Lophopterys, Malpighia, Mascagnia, Mcvaughia, Mezia, Microsteira, Mionandra, Peixotoa, Peregrina, Philgamia, Pterandra, Ptilochaeta, Rhynchophora, Rhyssopteris, Spachea, Sphedamnocarpus, Stigmaphyllon, Tetrapteris, Thryallis, Triaspis, Tricomaria, Triopteris, Tristellateia, Verrucularia.
Economic uses, etc. Edible fruit from Malphigia glabra (Brasilian cherry, pitanga etc.).
Illustrations. • Acridocarpus macrocalyx: Thonner. • Le Maout and Decaisne: Hiraea, Malpighia, ‘Banisteria’. • Le Maout and Decaisne: Burdachia, Byrsonima, Coleostachys, Diplopterys, Malpighia, Rhyssopterys: Lindley. • Aspidopterys indica, as Hiraea: R. Wight, Ic. Pl. Indiae Orientalis 2 (1843). • Triaspis hypericoides subsp. nelsonii: Hook. Ic. Pl. 15 (1883). • Stigmaphyllon aristatum: Bot. Reg. 1659, 1835. • Stigmaphyllon jatrophaefolium: Bot. Reg. 1844, 7. • Thryallis longifolia: Martius, Nova Gen. et Spec. Pl. Brasiliensium 3 (1829). • Leaf hairs of Camarea, Hiraea, Lophopterys, Malpighia, Mascagnia, Peixotoa, Thryallis (Solereder, 1908). • Heteropteris and Tetrapteris: TS grooved stems, showing split xylem (Solereder, 1908).
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: 15th April 2018. delta-intkey.com/angio’.