Annuals, dwarf shrubs or shrubs, covered with bladder and small (almost invisible) simple hairs of white or brown colour. Leaves alternate or opposite, flat (but in some cases folded on ventral side), with C3 or C4 photosynthetic pathway (in the latter case, the bundles have a chlorenchyma sheath that looks like dark-green stripes near the veins). Flowers bisexual (rare) and unisexual (plants monocious or diocious), arranged in clusters forming loose or dense inflorescences. Male flowers with (3-4) 5 hyaline segments connate at base and 4-5 stamens. Female flowers usually without (actinomorphic) perianth, enclosed in a bract-like cover (termed as “bracteoles” in literature pre-2011) formed of two accrescent and flattened perianth segments, often with outgrowths or appendages on the dorsal part (the term “valves” is used to describe here their morphology); in addition to the female flowers enclosed in valves, three species have also female flowers with actinomorphic perianth of (3-4) 5 segments (accordingly, this flower-type lacks the flattened valves). Stigmas style-like (stylodia) 2, rarely 3. Seeds rounded, elliptic or ovoid, with perisperm; embryo vertical in seeds formed in flowers enclosed in valves, and horizontal in seeds of female or bisexual flowers with actinomorphic perianth (“spatial heterospermy”).