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; without marked odour; 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. Leaves without a persistent basal meristem. Domatia occurring in the family (Acridocarpus); manifested as hair tufts.
Leaf anatomy. Mucilaginous epidermis present, or absent. Hairs present; unicellular. Unicellular hairs branched (peculiar). Urticating hairs present (occasionally), or absent.
Minor leaf veins without phloem transfer cells (Malpighia).
Stem anatomy. Cork cambium present; initially deep-seated (rarely), or superficial. Nodes tri-lacunar, or unilacunar. Cortical bundles absent. Internal phloem present, or absent. Secondary thickening anomalous (frequently), or developing from a conventional cambial ring; from a single cambial ring. The secondary phloem stratified into hard (fibrous) and soft (parenchymatous) zones, or not stratified. ‘Included’ phloem present (commonly), or absent. Xylem with libriform fibres; with vessels. Vessel end-walls simple. Vessels with vestured pits. Wood parenchyma apotracheal, or paratracheal, or apotracheal and paratracheal (predominantly paratracheal in most genera, but predominantly apotracheal in a few including Malpighia).
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 unit 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 neither papilionaceous nor pseudo-papilionaceous; 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 (3–5 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 obliquely positioned (when G3 (i.e. usually)). 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, biochemistry. Cyanogenic (doubtfully), or not cyanogenic. Alkaloids present, or absent. Iridoids detected (known only from Stigmaphyllon); ‘Route I’ type (?). Proanthocyanidins present, or absent; when present, cyanidin. Flavonols present, or absent; kaempferol, or kaempferol and quercetin. Ellagic acid absent (4 species, 4 genera). Saponins/sapogenins present (rarely), or absent. Aluminium accumulation not found. Sugars transported as sucrose (Byrsonima), or as oligosaccharides + sucrose (Lophanthera). Inulin recorded. Anatomy non-C4 type (Tristellateia).
Geography, cytology. Sub-tropical to tropical. Pantropical, concentrated in South America. X = 6, 9–12(+).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae; Polygalales. Cronquist’s Subclass Rosidae; Polygalales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; 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.).
• Technical details: Acridocarpus (Thonner).
• Technical details: Hiraea, Malpighia, ‘Banisteria’.
• Technical details: Burdachia, Byrsonima, Coleostachys, Diplopterys, Malpighia, Rhyssopterys (Lindley).
• Stigmaphyllon aristatum: Bot. Reg. 1659, 1835.
• Stigmaphyllon jatrophaefolium: Bot. Reg. 1844, 7.