The Families of Flowering Plants
The Families of Flowering Plants | |
Habit and leaf form. ‘Arborescent’, or shrubs; without essential oils (or nearly so). Leaves evergreen; alternate; spiral to distichous; simple. Lamina dissected to entire; when dissected, pinnatifid (lobed); pinnately veined. Leaves exstipulate.
Leaf anatomy. Stomata present; anomocytic, or paracytic.
The mesophyll without etherial oil cells.
Stem anatomy. Nodes unilacunar (with one broad trace). Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem presumably with tracheids; without vessels. Primary medullary rays narrow. Sieve-tube plastids S-type.
Reproductive type, pollination. Plants dioecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’. The terminal inflorescence unit cymose. Inflorescences axillary. Flowers partially acyclic. The perianth acyclic. Floral receptacle markedly hollowed (more or less, in female flowers), or not markedly hollowed (slightly convex, in male flowers). Free hypanthium present.
Perianth sequentially intergrading from sepals to petals; 5–8; weakly joined (basally); spiralled.
Androecium in male flowers 30–100 (‘more or less numerous’). Androecial members maturing centripetally (?); of the outer cycle adnate (basally, to the tepals); free of one another; 3–5 whorled (‘in several cycles’). Androecium (male flowers) exclusively of fertile stamens. Stamens 30–100 (‘more or less numerous’); more or less laminar. Anthers adnate (with adaxial thecae); non-versatile; dehiscing via longitudinal slits; introrse. Pollen grains aperturate to nonaperturate; if detectably aperturate, obscurely 1 aperturate (or with an irregular, distal, unthickened zone in the exine); sulcate.
Gynoecium 5–8 carpelled; apocarpous; eu-apocarpous (the carpels in a single whorl); superior. Carpel incompletely closed (unsealed at the tip); with a sessile stigma having two expanded flanges; 1 ovuled. Placentation marginal. Ovary stipitate. Ovules anatropous.
Fruit an aggregate. The fruiting carpel indehiscent; drupaceous (stipitate). Seeds endospermic. Embryo well differentiated (minute, basal). Cotyledons 2.
Physiology, biochemistry. Aluminium accumulation demonstrated.
Geography, cytology. Paleotropical. New Caledonia. N = 13 (2n = 26).
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Laurales. Cronquist’s Subclass Magnoliidae; Laurales. APG (1998) oddment family (but really ‘basal'?). Species 1. Genera 1; Amborella trichopoda the only species.
The 1999 International Botanical Congress (St. Louis) candidate for ‘the most primitive Angiosperm'!.
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’.