The Families of Flowering Plants
The Families of Flowering Plants | |
~ Myrtaceae
Habit and leaf form. Small trees. Leaves alternate; spiral; petiolate; non-sheathing; gland-dotted (pellucid punctate); simple. Lamina entire; pinnately veined (without an intramarginal vein); cross-venulate. Leaves stipulate. Lamina margins entire. Domatia occurring in the family; manifested as pockets.
Leaf anatomy. Lamina with secretory cavities.
Stem anatomy. Internal phloem present (?). Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids; without libriform fibres.
Reproductive type, pollination. Plants hermaphrodite.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in panicles. Inflorescences terminal; terminal thyrses. Flowers small; regular; 5 merous; cyclic; tetracyclic. Free hypanthium present (the corolla ‘inserted on the calyx tube’).
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; polysepalous, or gamosepalous; five blunt-lobed; regular; persistent; scarcely imbricate, or open in bud. Corolla 5; 1 whorled; polypetalous (the small petals inserted on the hypanthium/calyx tube). Petals shortly clawed (and gland dotted).
Androecium 5. Androecial members free of the perianth (inserted on the tube); all equal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; alternisepalous; opposite the corolla members; inflexed in bud. Anthers dorsifixed; dehiscing via longitudinal slits; introrse; appendaged (with a well developed connective gland). The anther appendages apical. Pollen grains aperturate; 3 aperturate; (parasyn-) colporate.
Gynoecium 2–3 carpelled. Carpels reduced in number relative to the perianth. The pistil 2–3 celled. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 2–3 locular; sessile. Gynoecium stylate. Styles 1; from a depression at the top of the ovary; apical; short, persistent. Stigmas 1; capitate. Placentation axile (the ovules over most of the peltate placenta). Ovules 30–50 per locule (‘many’, no ovulodes); hemianatropous, or campylotropous (?).
Fruit non-fleshy; dehiscent; a capsule. Capsules loculicidal (small, 2–3 locular). Seeds non-endospermic. Cotyledons 2; flat. Embryo straight.
Geography, cytology. Paleotropical. Tropical. South Africa.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Myrtiflorae; Myrtales. Cronquist’s Subclass Rosidae; Myrtales. APG (1998) Eudicot; core Eudicot; Rosid; Eurosid II; Myrtales. Species 3. Genera 1; only genus, Heteropyxis.
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’.