The families of flowering plants.
IncludingHenslowiaceae Lindl. corr. Endl.Excluding Alzateaceae, Rhynchocalycaceae
Habit and leaf form. Trees, or shrubs. Helophytic, or mesophytic. Leaves opposite; leathery; petiolate; not gland-dotted; simple. Lamina entire; pinnately veined (with a continuous submarginal vein); cross-venulate (brochidodromous). Leaves stipulate to exstipulate (the stipules rudimentary, lateral). Lamina margins entire.
Leaf anatomy. Stomata present; anomocytic (Dactylocladus), or paracytic.
The mesophyll with sclerencymatous idioblasts (unbranched), or without sclerenchymatous idioblasts (Axinandra); containing calcium oxalate crystals. The mesophyll crystals druses.
Stem anatomy. Young stems tetragonal, or flattened. Cork cambium present; initially deep-seated, or superficial (Dactylocladus). Nodes unilacunar. Primary vascular tissue bicollateral. Internal phloem present. Secondary thickening developing from a conventional cambial ring, or anomalous (?). ‘Included’ phloem absent. Xylem with fibre tracheids (non-septate); with vessels. Vessel end-walls simple. Vessels with vestured pits. Wood parenchyma paratracheal.
Reproductive type, pollination. Plants hermaphrodite, or polygamodioecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in racemes, or in spikes, or in panicles. Inflorescences axillary; racemes, spikes or panicles of subsessile flowers. Flowers numerous, very small; regular; 4–5(–6) merous. Free hypanthium present (this cupular or shortly tubular). Hypogynous disk absent.
Perianthwith distinct calyx and corolla, or sepaline (the corolla absent in Crypteronia);(8–)10, or 4–5(–6) (Crypteronia); 1 whorled, or 2 whorled; isomerous. Calyx 4–5(–6); 1 whorled; polysepalous (on the hypanthium?), or gamosepalous (? — the lobes (or sepals) thin, membranous); 4–5(–6) blunt-lobed; persistent, or not persistent (Axinandra); valvate. Corollawhen present, (4–)5; 1 whorled; polypetalous, or gamopetalous (Axinandra); deciduous (as a coneshaped unit in Axinandra, the individual petals falling in the other genera).
Androecium 4–5(–6), or 10 (Axinandra). Androecial members free of the perianth, or adnate (epipetalous and episepalous in Axinandra); free of one another; 1 whorled, or 2 whorled (Axinandra). Androecium exclusively of fertile stamens. Stamens 4–5(–6), or 10; isomerous with the perianth, or diplostemonous; alternisepalous, or oppositisepalous (?); filantherous (the filaments long or short). Anthers small; tetrasporangiate (the sporangia lateral to terminal). Anther wall of the ‘dicot’ type (in Axinandra). Pollen shed as single grains. Pollen grains aperturate; 4–6 aperturate; colpate and colporate (bisyncolporate with two indistinct subsidiary colpi (Crypteronia), or tricolporate with three distinct subsidiary colpi); 2-celled.
Gynoecium 2(–4) carpelled (Crypteronia), or (3–)4–5 carpelled (Dactylocladus), or (2–)3 carpelled (Axinandra). Carpels reduced in number relative to the perianth to isomerous with the perianth. The pistil 1(–5) celled. Gynoeciumsyncarpous; eu-syncarpous; superior to inferior. Ovary unilocular;1 locular (but the septa sometimes joined basally). Epigynous disk absent. Gynoecium stylate. Styles 1; attenuate from the ovary; apical; much longer than the ovary (persistent complete with the stigma, or (Axinandra) non-persistent). Stigmas 1; capitate (or punctate). Placentation basal, or basal to parietal. Ovules in the single cavity 6–15; horizontal, or ascending; anatropous. Outer integument contributing to the micropyle (in Axinandra). Embryo-sac development Polygonum-type (Axinandra).
Fruit non-fleshy; dehiscent; a capsule (indurated). Capsules loculicidal and valvular (2–5 valved, the valves usually remaining connected at the style). Fruit50–100 seeded (‘many’). Seeds non-endospermic; small; winged (at the micropylar or chalazal end), or wingless. Cotyledons 2. Embryo central or basal. Micropyle not zigzag.
Physiology, biochemistry. Aluminium accumulation demonstrated.
Geography, cytology. Paleotropical. Tropical. Tropical Asia.
Taxonomy.Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; malvid; Order Myrtales.
Species 10. Genera 3; Crypteronia, Axinandra, Dactylocladus.