The Families of Flowering Plants
The Families of Flowering Plants |
|
Habit and leaf form. Small trees, or shrubs, or lianas; non-laticiferous and without coloured juice. Self supporting, or climbing. Leaves evergreen, or deciduous; alternate; ‘herbaceous’, or leathery; petiolate; non-sheathing; simple. Lamina entire; pinnately veined; cross-venulate. Leaves stipulate. Stipules free of one another; caducous (small, linear-lanceolate). Lamina margins serrate (or serrulate).
Leaf anatomy. Stomata present; mainly confined to one surface (abaxial); anomocytic.
The mesophyll without sclerenchymatous idioblasts; containing calcium oxalate crystals. The mesophyll crystals druses. Minor leaf veins without phloem transfer cells.
Stem anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids; with vessels. Vessel end-walls scalariform. Wood parenchyma apotracheal.
Reproductive type, pollination. Plants hermaphrodite, or polygamomonoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; pendulous, in racemes, or in spikes. The terminal inflorescence unit racemose. Inflorescences terminal, or axillary; pendulous racemes or spikes. Flowers bi- bracteolate (the bracteoles connate); small; regular; 4 merous (throughout); cyclic; polycyclic. Free hypanthium absent.
Perianth with distinct calyx and corolla; 8; 3 whorled; isomerous. Calyx 4; 2 whorled (2+2); polysepalous; regular; much imbricate. Corolla 4; 1 whorled; polypetalous (the petals connivent); imbricate; regular. Petals sessile.
Androecium 8. Androecial members free of the perianth; free of one another; 2 whorled. Androecium exclusively of fertile stamens. Stamens 8; diplostemonous; filantherous (the filaments subulate). Anthers appearing versatile; dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen grains aperturate; 3(–4) aperturate; (tri-) colporate (occasionally 4-ruporate); 2-celled, or 3-celled.
Gynoecium 4 carpelled. Carpels isomerous with the perianth. The pistil 1 celled, or 4 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular, or 4 locular (4-locular at the base, but above and for most of it length the partitions, though deeply intruded, are not united in the middle). Gynoecium shortly stylate. Styles 1; apical. Stigmas 1; obscurely 4 lobed; capitate to subpeltate; wet type; papillate; Group I type. Placentation parietal (above); axile (below). Ovules 30–50 per locule (‘numerous’); arillate; anatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped. Endosperm formation nuclear.
Fruit fleshy; indehiscent; a berry (rather firm and dry, 4-locular); many seeded. Seeds endospermic. Endosperm oily (and proteinaceous). Seeds small. Embryo well differentiated. Cotyledons 2 (flat). Embryo straight.
Physiology, biochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins present, or absent; cyanidin. Flavonols present; kaempferol and quercetin. Ellagic acid present. Arbutin absent. Aluminium accumulation not found.
Geography, cytology. Holarctic. Temperate to tropical. Eastern Asia - Himalayas to Formosa and Japan.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Theiflorae (?); Theales (?). Cronquist’s Subclass Dilleniidae; Violales. APG (1998) Eudicot; core Eudicot; Rosid; unassigned to Eurosid I or Eurosid II; unassigned to order. Species 10. Genera 1; only genus, Stachyurus.
Illustrations. • Stachyurus.
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: 10th April 2008. http://delta-intkey.com’.
