~ Saxifragaceae, Grossulariaceae
Habit and leaf form. Shrubs, or trees; non-laticiferous and without coloured juice. Mesophytic. Leaves alternate, or opposite, or whorled; `herbaceous', or leathery, or fleshy; petiolate; non-sheathing; not gland-dotted; simple; epulvinate. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins crenate, or serrate, or dentate (the teeth mostly gland-tipped). Vegetative buds scaly, or not scaly. Leaves without a persistent basal meristem. Domatia recorded (Carpodetus); represented by pockets.
Leaf anatomy. Stomata present; anomocytic (mostly), or paracytic, or cyclocytic. Hairs present; unicellular.
Adaxial hypodermis present (commonly), or absent. Lamina dorsiventral; without secretory cavities. Minor leaf veins without phloem transfer cells (Corokia, Escallonia).
Stem anatomy. Secretory cavities absent. Cork cambium present; initially deep-seated, or superficial. Nodes unilacunar, or tri-lacunar, or penta-lacunar (Argophyllum). Secondary thickening developing from a conventional cambial ring. Xylem with tracheids. Vessel end-walls scalariform. Primary medullary rays tending to be mixed wide and narrow. Wood parenchyma apotracheal (diffuse).
Reproductive type, pollination. Hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'. The terminal inflorescence unit cymose, or racemose. Flowers regular; (4-)5(-6) merous; cyclic. Floral receptacle with neither androphore nor gynophore. Free hypanthium present, or absent. Hypogynous disk present.
Perianth with distinct calyx and corolla; (8-)10(-12); 2 whorled; isomerous. Calyx (4-)5(-6); 1 whorled; polysepalous, or gamosepalous; regular; persistent; imbricate, or valvate; with the odd member posterior. Corolla (4-)5(-6); 1 whorled; not appendiculate; polypetalous (nearly always), or gamopetalous (rarely, with a short tube); imbricate, or valvate; regular. Petals clawed, or sessile.
Androecium (4-)5(-6), or (8-)10(-12). Androecial members free of the perianth (perigynous); free of one another; 1 - whorled, or 2 - whorled. Androecium exclusively of fertile stamens (when only one whorl), or including staminodes (when two whorls). Staminodes when present, (4-)5(-6). Stamens (4-)5(-6); isomerous with the perianth; (fertile) oppositisepalous. Anthers dorsifixed; dehiscing via longitudinal slits; introrse. Pollen shed in aggregates (Carpodetus), or shed as single grains; in Carpodetus, in tetrads. Pollen grains aperturate; 3 - aperturate; colporate; 3-celled.
Gynoecium 1-6. Carpels reduced in number relative to the perianth (usually), or isomerous with the perianth. Gynoecium apocarpous (rarely), or syncarpous; eu-apocarpous (rarely), or semicarpous to eu-syncarpous; superior to inferior. Carpel (when apocarpous) 15-100 ovuled (`many'). Placentation when apocarpous marginal. Ovary when syncarpous 1 locular, or 2-6 locular. Gynoecium stylate. Styles 1-6; apical. Stigmas wet type; non-papillate; Group IV type. Placentation when unilocular parietal; when plurilocular axile. Ovules in the single cavity when unilocular, 15-100 (`many'); when plurilocular, 15-50 per locule (`many'); anatropous; unitegmic, or bitegmic; tenuinucellate, or crassinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids elongated. Endosperm formation nuclear.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a capsule, or a berry. Seeds copiously endospermic. Endosperm oily.
Physiology, biochemistry. Not cyanogenic. Iridoids recorded; carbocyclic. Proanthocyanidins present, or absent; when present, cyanidin, or delphinidin. Flavonols present; kaempferol, or quercetin, or kaempferol and quercetin (mostly both). Ellagic acid absent (6 species, 3 genera). Aluminium accumulation demonstrated (rarely), or not found.
Geography, cytology. Temperate to tropical. Tropical and South temperate, mostly South America and Australasia.
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren's Superorder Corniflorae; Cornales. Cronquist's Subclass Rosidae; Rosales. Takhtajan's Subclass Rosidae; Rosanae; Saxifragales. Species 150. Genera about 11; Abrophyllum, Anopterus, Argophyllum, Carpodetus, Corokia, Cuttsia, Escallonia, Forgesia, Polyosma, Quintinia, Valdivia.
Illustrations. escal393.gif
