The Families of Flowering Plants
The Families of Flowering Plants | |
Habit and leaf form. Shrubs; bearing essential oils. Plants non-succulent. Leaves evergreen; small; alternate; leathery; shortly petiolate; non-sheathing; not gland-dotted; aromatic, or without marked odour (?); simple. Lamina entire; lanceolate to oblanceolate, or ovate to obovate; one-veined, or pinnately veined (?). Leaves exstipulate. Lamina margins entire.
Leaf anatomy. Stomata present; mainly confined to one surface (abaxial), or on both surfaces; anomocytic.
Lamina dorsiventral. Minor leaf veins without phloem transfer cells (Cneorum).
Stem anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with libriform fibres. Vessel end-walls simple. Wood partially storied (VP); parenchyma predominantly paratracheal.
Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; when solitary, axillary; when aggregated, in cymes, or in corymbs. The terminal inflorescence unit cymose. Inflorescences axillary (the peduncle sometimes adnate to the petiole); small, few flowered axillary corymbs. Flowers small; regular; 3 merous (Cneorum), or 4 merous (Neochamaelea). Floral receptacle developing an androphore (this nectariferous, shortly columnar). Free hypanthium absent.
Perianth with distinct calyx and corolla; 6, or 8 (Neochamaelea); 2 whorled; isomerous. Calyx 3, or 4; 1 whorled; polysepalous, or gamosepalous (basally). Calyx lobes when gamosepalous, markedly longer than the tube. Calyx regular; persistent (small). Corolla polypetalous (the petals elongate); imbricate.
Androecium 3, or 4. Androecial members free of the perianth; all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 3, or 4; isomerous with the perianth; oppositisepalous; alternating with the corolla members; filantherous (the filaments seated in pits in the androgynophore). Anthers dorsifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate. Pollen shed as single grains. Pollen grains aperturate; 3 aperturate, or 4–6 aperturate; colporate; 3-celled.
Gynoecium 3 carpelled, or 4 carpelled. Carpels isomerous with the perianth. The pistil 3 celled, or 4 celled, or 6 celled, or 8 celled. Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 3 locular, or 4 locular. Locules partially secondarily divided by ‘false septa’, or without ‘false septa’. Gynoecium stylate. Styles 1; apical. Placentation apical. Ovules (1–)2 per locule; pendulous; epitropous; with ventral raphe; collateral, or superposed (the two commonly more or less separated by an intrusion from the carpellary midrib); anatropous to amphitropous; bitegmic (the outer integument scarcely developed on the raphal side); crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating. Synergids pear-shaped. Endosperm formation nuclear. Embryogeny asterad.
Fruit fleshy, or non-fleshy; a schizocarp. Mericarps 3, or 4, or 6, or 8; comprising drupelets (the 1–2 seeded mericarps separating, and the fruit wall assuming the protective functions of the reduced testa). Seeds copiously endospermic. Endosperm oily. Embryo well differentiated. Cotyledons 2. Embryo achlorophyllous (1/1); strongly curved (in the curved seed).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Not cyanogenic. Iridoids not detected. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid absent (Cneorum).
Geography, cytology. Holarctic and Neotropical. Temperate (warm), or sub-tropical to tropical. Cuba, Canaries, Mediterranean. X = 9.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Rutiflorae; Rutales. Cronquist’s Subclass Rosidae; Sapindales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Sapindales (as a synonym of Rutaceae). Species 3. Genera 2; Cneorum, Neochamaelea.
Illustrations. • Technical details (Cneorum).
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’.
