The Families of Flowering Plants
The Families of Flowering Plants | |
~ Datiscaceae
Habit and leaf form. Large, often buttressed trees. Mesophytic. Leaves alternate; petiolate; non-sheathing; simple. Lamina entire; ovate; palmately veined; cross-venulate; cordate. Leaves exstipulate. Lamina margins entire, or dentate. Leaves without a persistent basal meristem.
Leaf anatomy. Stomata present; anomocytic.
Lamina dorsiventral. The mesophyll with sclerencymatous idioblasts (at least in Octomeles). Minor leaf veins without phloem transfer cells (Tetrameles).
Stem anatomy. Cork cambium present; initially superficial. Secondary thickening developing from a conventional cambial ring. Vessel end-walls simple. Wood partially storied (VPI); parenchyma paratracheal.
Reproductive type, pollination. Plants dioecious. Female flowers without staminodes.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in spikes and in panicles. Inflorescences terminal, or axillary; terminal panicles or axillary, solitary spikes. Flowers regular to somewhat irregular; cyclic. Free hypanthium present (the corolla inserted on the calyx).
Perianth with distinct calyx and corolla, or sepaline; 4, or 12–16; 1 whorled, or 2 whorled; isomerous. Calyx 4, or 6–8; 1 whorled; gamosepalous; unequal but not bilabiate, or regular; valvate. Corolla when present, 6–8; 1 whorled; polypetalous; valvate.
Androecium 4, or 6–8. Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens (in the male flowers). Stamens 4, or 6–8; isomerous with the perianth. Anthers dorsifixed; dehiscing via longitudinal slits; extrorse; bilocular. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 4 carpelled, or 6–8 carpelled. Carpels isomerous with the perianth. The pistil 1 celled. Gynoecium syncarpous; synovarious; inferior. Ovary 1 locular. Gynoecium stylate. Styles 4, or 6–8; free; apical. Placentation parietal. Ovules in the single cavity 20–100 (‘many’); pendulous to horizontal; anatropous; bitegmic.
Fruit non-fleshy; dehiscent; a capsule. Capsules valvular. Fruit 20–100 seeded (‘many’). Seeds scantily endospermic, or non-endospermic (?); minute. Embryo straight.
Peculiar feature. The young, syncarpous unilocular gynoecium and later the capsule open.
Geography, cytology. Tropical. Southeast Asia, Malaysia, Australia. X = 11, 23 (or more).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae (?); Myrtales (? - cf. Lythraceae). Cronquist’s Subclass Dilleniidae; Violales. APG 3 core angiosperms; core eudicot; Superorder Rosanae; fabid; Order Cucurbitales.
Species 2. Genera 2; Tetrameles, Octomeles.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using 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 specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2009. http://delta-intkey.com’.