Herbs with rhizomes. Usually perennial, some annual. Sometimes stoloniferous. Pachycaul. Nostoc punctiforme or Chlorococcus colonies in stem (rhizoms) and root (Nitrogen-fixing) or in warts. The difference in anatomy between stems and stolons is striking. Cork present
Distribution
Temperate to tropical and southern temperate areas. In Neotropics Central and South America, South Pacific. Africa. Southern hemisphere. confined to misty cliffs or deep shady gulches. Aquatic environment tollerated (some genera are always associated with water, growing along streams, near springs and in seepage or marshy areas).
Floral characters
Basal flowers often female, upper ones male and middle ones bisexual or dioecious. very small, unisexual and then plants monoecious or diecious, or bisexual. 2(3) or almost (0) Sepals (small, valvate), 0-2 Petals, usually missing, mitre-shaped. A1-2 Stamens (with short filaments and anthers with longitudinal slits). Ovary inferior, G(2)1-locular, with 2 terminal styles, stigmas papillate, 1 pendulous, anatropous and bitegmic ovule.
Leaf characters
Alternate, rosulate, spirally arranged, orbicular or ovate basal aggregation of leaves (the leaves all radical) strongly petiolate; sheathing; simple; often peltate; epulvinate. lamina without secretory cavities, minor leaf veins without phloem transfer cells.Often pachycaul. Helophytic, or mesophytic. with intrapetiolar stipules and blades that have very prominint venation (palmately veined) on the lower surface. often long-petiolate and with very large orbicular to reniform lamina, with large axillary 'stipular' scales.The lamina varies from 7 mm to m across, and the teeth have a glandular apex that broadens distally.
Stipules
present, intrapetiolar
Fruit characters
Fleshy drupe, or a nut. Indehiscent. The drupes with one stone. Seed contains a very small embryo, embedded in copious oily endosperm.
Glands
present, glandular apex
Hairs
present
Latex
absent
Odor
na
Uses
Ornamentals (Gunnera spec.) Partially for tanning (Gunnera chiensis) Medicinal (Gunnera pilosa, perpense) Edible (Gunnera perpense) used to prepare a spinach.
Chemical characters
Not cyanogenic. Iridoids not detected. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid present
Distribution maps
(online von http://www.mobot.org/MOBOT/research/APweb/ . Dort zitiert wie unter jedem Diagramm vermerkt):
Gunneraceae
map: see van Balgooy 1975; Wanntorp & Wanntorp 2003; fossil records [green] from the Late Cretaceous, see Jarzen & Dettmann 1989, also Osborne & Sprent 2002
