The families of flowering plants
~ Chenopodiaceae, Amaranthaceae.
Habit and leaf form. Herbs. Plants succulent. Annual. Leaves alternate; fleshy; simple; exstipulate.
Axial (stem, wood) anatomy. Internal phloem absent. Secondary thickening developing from a conventional cambial ring (with normal stem anatomy).
The axial xylem with libriform fibres. Included phloem absent.
Reproductive type, pollination. Plants monoecious.
Inflorescence, floral, fruit and seed morphology. Flowers solitary (female flowers), or aggregated in inflorescences (male flowers). Inflorescences of male flowers in strobilate, terminal spikes, the female flowers solitary in the 45 uppermost leaf axils.
Perianth sepaline (male flowers), or absent (female flowers); of male flowers, 4; 1 whorled. Calyx (in the male flowers only) 4; 1 whorled; polysepalous (membranous).
Androecium 4. Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 4; isomerous with the perianth; alternisepalous; filantherous (the filaments long, filiform). Anthers versatile. Pollen shed as single grains. Pollen grains aperturate; 6 aperturate; foraminate (the apertures operculate).
Gynoecium 3 carpelled. Carpels reduced in number relative to the perianth. The pistil 1 celled. Gynoecium syncarpous; synstylovarious; superior. Ovary 1 locular. Styles 1; apical. Stigmas 3 (finally exserted). Placentation basal. Ovules in the single cavity 1; campylotropous (?).
Fruit fleshy. Gynoecia of adjoining flowers combining to form a multiple fruit (the aggregate enclosed in the swollen stem apex, forming a berrylike structure).
Physiology, phytochemistry. Sieve-tube plastids P-type; type III (a).
Geography, cytology. Antarctic. Temperate. Patagonia.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Caryophylliflorae; Caryophyllales. Cronquists Subclass Caryophyllidae; Caryophyllales. APG 3 core angiosperms; core eudicot; Superorder Caryophyllanae; Order Caryophyllales (as a synonym of Amaranthaceae).
Species 1 (H. ameghinoi). Genera 1; only genus, Halophytum.
General remarks. Seemingly exhibiting numerous differences from Amaranthaceae (q.v.), but the present compilation may under-estimate variation within that large assemblage.
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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 or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 19th October 2016. delta-intkey.com’.