The Families of Flowering Plants
The Families of Flowering Plants | |
Habit and leaf form. Shrubs (typically small, often ericoid). Plants non-succulent. Leaves opposite (decussate); leathery; imbricate (often), or not imbricate; petiolate to sessile; simple. Lamina entire; pinnately veined (with a continuous marginal vein). Leaves stipulate (the stipules vestigial), or exstipulate.
Leaf anatomy. Stomata present; mainly confined to one surface, or on both surfaces; anomocytic.
Lamina dorsiventral, or isobilateral, or centric. The mesophyll with sclerencymatous idioblasts; containing calcium oxalate crystals. The mesophyll crystals druses.
Stem anatomy. Cork cambium present; initially deep-seated (in the pericycle). Nodes unilacunar. Cortical bundles present, or absent. Internal phloem present. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with tracheids; with vessels. Vessel end-walls simple. Primary medullary rays narrow.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary to aggregated in ‘inflorescences’ (occasionally paired, often crowded); axillary (with the upper leaves); bracteate (the bracts often coloured); bracteolate (the bracteoles opposite, in one or more pairs); regular; 4 merous; cyclic; tricyclic. Free hypanthium present. Hypogynous disk absent.
Perianth sepaline (but the hypanthium and calyx often coloured like a corolla); 4; 1 whorled; sepaloid, or petaloid. Calyx 4; 1 whorled; polysepalous (as lobes on the hypanthium); regular; persistent (with the hypanthium); valvate.
Androecium 4. Androecial members free of the perianth (attached to the hypanthium); free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4; isomerous with the perianth; alternisepalous; filantherous (the filaments very short). Anthers basifixed (the connective much expanded, thickly laminar, often much longer than the ventral or marginal, frequently well separated thecae); dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged, or unappendaged (?). Pollen shed as single grains. Pollen grains aperturate; 3–5 aperturate, or 6–10 aperturate; colpate and colporate (the colpi alternating with colpoid grooves).
Gynoecium 4 carpelled. Carpels isomerous with the perianth. The pistil 4 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary plurilocular; 4 locular; sessile. Gynoecium stylate. Styles 1; apical. Stigmas 1; capitate or four-lobed. Placentation basal to axile, or axile, or axile to apical. Ovules 2–4 per locule; pendulous, or ascending, or pendulous and ascending; anatropous; bitegmic; crassinucellate. Outer integument contributing to the micropyle. Embryo-sac development Penaea-type. Polar nuclei fusing prior to fertilization. Endosperm formation nuclear. Embryogeny asterad.
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (surrounded by the persistent hypanthium). Seeds more or less non-endospermic. Embryo well differentiated. Cotyledons 2 (very small).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Aluminium accumulation not found.
Geography, cytology. Cape. Sub-tropical. Southernmost Africa. X = 11, 12.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Myrtales. Species 25. Genera 7; Brachysiphon, Endonema, Glischrocolla, Penaea, Saltera, Sonderothamnus, Stylapterus.
Illustrations. • Technical details (Penaea, `Sarcocolla'). • Technical details (Saltera).
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’.
