Distribution: World wide, especially xeric or saline habitats with centers of diversity in South America and Australia. The Texas flora includes 16 genera and 66 species, many of these common weeds of agricultural fields.
Significant features: A difficult family in that the flowers are small and the plants more or less 'streamlined' with few conspicuous characters. Elements of the family are, however, often common and ecologically important. Field recognition keys on an 'eye' focused on reduced flowers, often perfect but sometimes unisexual, producing the distinctive, often uniovulate 'beaked' fruit depicted below and a 'fleshy' or succulent aspect to the plant. Epigyny is rare in the family (only Beta).
Overview - Beta vulgaris - from Dr. Otto Wilhelm Thomé, Flora von Deutschland Österreich und der Schweiz
Chenopodium berlandieri with sectioned
(left - pericarp, testa, perisperm, embryo), whole fruit (center -
pericarp, darker testa, and 'beak' of the radical), and (right)flower
|Chenopodium missouriense - inflorescence - at anthesis||C. berlandieri flowers at anthesis||C. berlandieri fruit/seed
surface with dark testa, reticulate pericarp and 'beak' of
||C. berlandieri fruit/seed cross sectioned with testa, reticulate pericarp and 'beak' of the radical||C. berlandieri fruit in long
section with embryo, perisperm, testa and pericarp
The Amaranthaceae (pigweed family) is a 'sister' group to the Chenopodiaceae in that all working with classification of the Caryophyllales, regardless of approach, agree that the two families are closely related. They also share similarities in size, structure, ecological amplitude, and distribution. These two families are distingusished, for the most part, by connation in the perianth which is common in the Chenopodiaceae and rare in the Amaranthaceae.
More information on the Chenopodiaceae