Perennial herbs. Stipules adnate to petiole and
± sheathing the stem. Leaves circular or reniform in
outline, palmately lobed. Inflorescences axillary. Flowers small,
bisexual, green or yellowish, usually 4-merous. Hypanthium
urceolate, persistent, bearing around the constricted mouth 2
series of 4 elements: the outer ("epicalyx lobes") alternating
with the inner ("calyx lobes"). Petals 0. Stamens usually 4.
Achenes 1-8(-12), included within an inflated,
membranous urceolate calyx.
Worldwide: 250 species in northern temperate zones and on tropical mountains Zambia: 2 taxa. |
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