The families of flowering plants.
IncludingRibesieae (Ribesiaceae) A. Rich., Pulpaceae DulacExcludingBrexiaceae, Dulongiaceae, Escalloniaceae, Iteaceae,Montiniaceae, Pterostemonaceae
Habit and leaf form. Shrubs (often spiny); leptocaul. Mesophytic. Leaves deciduous; small, or medium-sized; alternate; spiral (often fascicled, on short-shoots); flat; petiolate; non-sheathing; aromatic, or without marked odour; simple. Lamina dissected; palmatifid; palmately veined; cross-venulate. Leaves stipulate, or exstipulate. Stipules when present, intrapetiolar (adnate to the petiole). Lamina margins entire to dentate; flat. Vegetative buds scaly. Leaves without a persistent basal meristem. Vernation plicate, or convolute. Domatia occurring in the family (Ribes); manifested as pockets.
Leaf anatomy. Lamina dorsiventral. Minor leaf veins without phloem transfer cells (1).
Stem anatomy. Cork cambium present; initially deep-seated. Nodes unilacunar, or tri-lacunar. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with fibre tracheids; with vessels. Vessel end-walls scalariform, or scalariform and simple, or simple. Wood parenchyma typically very rare or absent.
Reproductive type, pollination. Plants hermaphrodite, or dioecious. Pollination entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’ (or ‘subsolitary’); in racemes. The ultimate inflorescence unit racemose. Flowers bi- bracteolate; small to medium-sized; regular; 4–5 merous; cyclic; tetracyclic. Free hypanthium present.
Perianth with distinct calyx and corolla, or petaline; 8, or 10; 2 whorled; isomerous. Calyx 4, or 5 (sometimes petaloid); 1 whorled; gamosepalous; blunt-lobed; cupuliform, or campanulate; regular; persistent; sub- valvate, or imbricate. Corolla 4, or 5 (alternatively interpretable as staminodes); 1 whorled; polypetalous (the petals small, inserted in the hypanthium and alternating with the calyx lobes and stamens); imbricate; regular; persistent. Petals scalelike, obovate or subulate.
Androecium 4, or 5. Androecial members free of the perianth (inserted at the mouth of the hypanthium); all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens (assuming the ‘petals’ are not regarded as staminodes). Stamens 4, or 5; isomerous with the perianth; oppositisepalous. Anthers non-versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral. Anther wall initially with more than one middle layer. Pollen grains aperturate; (2–)3–11 aperturate; porate, or colporate, or rugate; 2-celled.
Gynoecium2 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious, or synstylovarious; inferior.Ovary 1 locular. Gynoecium median; stylate. Styles 2; free to partially joined; apical. Stigmas 2 (undivided); wet type; non-papillate; Group IV type. Placentation parietal. Ovules in the single cavity 4–100 (‘few to many’); funicled; horizontal; arillate; anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 2, or 3; not proliferating; ephemeral. Synergids hooked. Endosperm formation cellular, or helobial. Embryogeny irregular.
Fruit fleshy; indehiscent; a berry (pulpy, crowned by the persistent perianth); 20–100 seeded (‘many’). Seeds endospermic. Endosperm oily. Embryo well differentiated (rather small). Cotyledons 2. Embryo achlorophyllous (2/3); straight.
Physiology, biochemistry. Cyanogenic, or not cyanogenic. Cynogenic constituents tyrosine-derived (triglochinin?). Iridoids not detected. Proanthocyanidins present; cyanidin, or cyanidin and delphinidin. Flavonols present; kaempferol and quercetin, or kaempferol, quercetin, and myricetin. Ellagic acid present, or absent (variable in Ribes). Aluminium accumulation demonstrated. C3. C3 physiology recorded directly in Ribes.
Geography, cytology. Holarctic, Neotropical, and Antarctic. Frigid zone to sub-tropical. Temperate Eurasia, Northwest Africa, North and Central America, Pacific South America to Fuegia.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rosiflorae; Cunoniales. Cronquist’s Subclass Rosidae; Rosales. APG 3 core angiosperms; core eudicot; unplaced at Superordinal level; Order Saxifragales.
Species 150. Genera 2; Grossularia, Ribes.
Economic uses, etc. Commercial sources of edible fruits (redcurrants, whitecurrants, and gooseberries), and cultivated ornamental shrubs (e.g. Ribes sanguineum, Ribes aureum.