The Families of Flowering Plants
The Families of Flowering Plants | |
Habit and leaf form. Large trees; bearing essential oils. Leaves alternate; petiolate; non-sheathing; gland-dotted; aromatic; simple. Lamina entire; pinnately veined; cross-venulate. Leaves exstipulate. Lamina margins entire.
Leaf anatomy. Stomata present; paracytic.
Lamina without secretory cavities. The mesophyll with spherical etherial oil cells.
Stem anatomy. Nodes penta-lacunar (with five traces). Internal phloem absent. Secondary thickening developing from a conventional cambial ring. ‘Included’ phloem absent. Xylem with fibre tracheids; with vessels. Vessel end-walls oblique; scalariform. Wood parenchyma mainly apotracheal. Sieve-tube plastids P-type. Pith with diaphragms.
Reproductive type, pollination. Plants hermaphrodite. Pollination entomophilous; probably via beetles.
Inflorescence, floral, fruit and seed morphology. Flowers solitary (pendulous, on long peduncles); (supra) axillary; medium-sized to large; regular; cyclic; polycyclic. Floral receptacle not markedly hollowed (shortly raised). Free hypanthium absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; 15–21; 4–6 whorled; isomerous. Calyx 3; 1 whorled; polysepalous; persistent. Corolla 12–18 (the petals larger than the sepals); 3–5 whorled; polypetalous; fleshy; deciduous. Petals sessile.
Androecium about 30–50. Androecial members unbranched; maturing centripetally; free of the perianth; free of one another; 3–6 whorled (?). Androecium including staminodes. Staminodes 3–10 (?); internal to the fertile stamens (located between the stamens and the gynoecium, similar to the stamens but fewer); non-petaloid. Stamens 20–30 (in 3–4 series); laminar (flattened, oblong, three nerved). Anthers adnate (the thecae abaxial); non-versatile; dehiscing via longitudinal slits, or dehiscing by longitudinal valves; extrorse; tetrasporangiate (the four microsporangia paired, abaxial). Microsporogenesis simultaneous. Anther wall initially with more than one middle layer; of the ‘basic’ type. Tapetum glandular. Pollen shed as single grains. Pollen grains aperturate; 1 aperturate; sulcate; 2-celled.
Gynoecium 1 carpelled. The pistil 1 celled. Gynoecium monomerous; of one carpel; superior. Carpel incompletely closed (largely unsealed at anthesis); non-stylate (the stigmatic surfaces running along the apposed margins); about 20–32 ovuled. Placentation more or less marginal (a single row towards each margin of the carpel). Ovules long funicled (in one series), or sessile (in the other); with a conspicuous funicular obturator; anatropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Endosperm formation cellular.
Fruit non-fleshy (leathery, with a hard exocarp). The fruiting carpel dehiscent, or indehiscent (?). Fruit 20–30 seeded. Seeds copiously endospermic. Endosperm ruminate; oily. Seeds flattened, more or less sculptured, with an orange-red sarcotesta. Embryo well differentiated (but very small). Cotyledons 3(–4).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Cyanogenic.
Geography, cytology. Paleotropical. Tropical. Fiji. 2n = 24.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Magnoliales. Cronquist’s Subclass Magnoliidae; Magnoliales. APG 3 core angiosperms; Superorder Magnolianae; Order Magnoliales.
Species 1. Genera 1; only genus, Degeneria.
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’.