Gyrocarpaceae Dum.
~ Hernandiaceae
Habit and leaf form. Small trees, or shrubs, or lianas. Self supporting, or climbing. Mesophytic. Leaves alternate; petiolate; non-sheathing; simple. Lamina dissected, or entire; when dissected, palmatifid; palmately veined; cross-venulate. Leaves exstipulate; without a persistent basal meristem.
Leaf anatomy. Stomata anomocytic.
Adaxial hypodermis present. Lamina dorsiventral; without secretory cavities. Cystoliths present. The mesophyll with spherical etherial oil cells.
Stem anatomy. Secretory cavities absent. Nodes unilacunar (with two traces). Primary vascular tissue in a cylinder, without separate bundles. Secondary thickening developing from a conventional cambial ring. Xylem with fibre tracheids. Wood parenchyma paratracheal. Sieve-tube plastids P-type; type I (b).
Reproductive type, pollination. Plants andromonoecious, or polygamomonoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’; in cymes, in corymbs, and in panicles. The terminal inflorescence unit cymose. Inflorescences dense thyrses. Flowers cyclic. Free hypanthium absent.
Perianth sepaline; (4–)8 (male flowers), or 2 (bisexual flowers); joined; 1 whorled. Calyx (if the perianth be so interpreted) (4–)8 (male flowers), or 2 (or at least, 2-lobed, in bisexual flowers); gamosepalous; persistent; in bisexual flowers accrescent (and winged); imbricate (in male flowers).
Androecium 3–5, or 6–9 (when staminodes present). Androecial members free of the perianth; free of one another; 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens, or including staminodes (these sometimes present in male as well as in bisexual flowers). Staminodes when present, 3–7. Stamens 3–5. Anthers basifixed; dehiscing by longitudinal valves; latrorse. Pollen grains nonaperturate.
Gynoecium 1 carpelled. The pistil 1 celled. Gynoecium monomerous; of one carpel; inferior. Carpel 1 ovuled. Placentation marginal.
Fruit non-fleshy. The fruiting carpel indehiscent (winged via the persistent, accrescent lobes of the perianth). Seeds non-endospermic. Cotyledons 2 (leafy, convolute).
Physiology, biochemistry. Alkaloids present. Aluminium accumulation not found.
Geography, cytology. Sub-tropical to tropical. Pantropical and subtropical.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgren’s Superorder Magnoliiflorae; Laurales. Cronquist’s Subclass Magnoliidae; Laurales. APG (1998) basal order; Laurales (as a synonym of Hernandiaceae). Species 22. Genera 2; Gyrocarpus, Sparattanthelium.
Illustrations. • Technical details (Gyrocarpus, Sparattanthelium).
Cite this publication as: ‘L. Watson and M. J. Dallwitz (1992 onwards). The Families of Flowering Plants: Descriptions, Illustrations, Identification, and Information Retrieval. Version: 14th December 2000. http://biodiversity.uno.edu/delta/’. Dallwitz (1980), Dallwitz, Paine and Zurcher (1993, 1995, 2000), and Watson and Dallwitz (1991) should also be cited (see References).
