Box 4. Dispersal syndromes

(1) Unassisted dispersal; the seed or fruit has no obvious aids for longer-distance transport and merely falls passively from the plant.

(2) Wind dispersal (anemochory) includes (A) minute dust-like seeds (e.g. Pyrola, Orchidaceae), (B) seeds with pappus or other long hairs (e.g. willows (Salix), poplars (Populus), many Asteraceae), ‘balloons’ or comas (trichomes at theendof a seed), (C) flattened fruits or seeds with large‘wings’, as seen in many shrubs and trees (e.g. Acer, birch (Betula), ash (Fraxinus), lime (Tilia), elm (Ulmus), pine (Pinus)); spores of ferns and related vascular cryptogams (Pteridophyta) and (D) ‘tumbleweeds’, where the whole plant or infructescence with ripe seeds is rolled over the ground by wind force, thereby distributing the seeds. The latter strategy is known from arid regions, e.g. Baptisia lanceolata in the south-eastern USA and Anastatica hierochuntica (rose-of-Jericho) in northern Africa and the Middle East.

(3) Internal animal transport (endo-zoochory), e.g. by birds, mammals, bats; many fleshy, often brightly coloured berries, arillate seeds, drupes and big fruits (often brightly coloured), that are evidently eaten by vertebrates and pass through the gut before the seeds enter the soil elsewhere (e.g. holly (Ilex), apple (Malus)).

(4) External animal transport (exo-zoochory); fruits or seeds that become attached e.g. to animal hairs, feathers, legs, bills, aided by appendages suchas hooks, barbs, awns, burs or sticky substances (e.g. burdock (Arctium), many grasses).

(5) Dispersal by hoarding; brown or green seeds or nuts that are hoarded and buried by mammals or birds.Tough, thick-walled, indehiscent nuts tend tobe hoarded by mammals (e.g. hazelnuts (Corylus) by squirrels) and rounded, wingless seeds or nuts by birds (e.g. acorns (Quercus spp.) by jays).

(6) Ant dispersal (myrmecochory); dispersules with elaiosomes (specialised nutritious appendages) that make them attractive for capture, transportand use by ants or related insects.

(7) Dispersal by water (hydrochory); dispersules are adapted to prolonged floating on the water surface, aided for instance by corky tissues and low specific gravity (e.g. coconut).

(8) Dispersal by launching (ballistichory); restrained seeds that are launched away from the plant by‘explosion’as soon as the seed capsule opens (e.g. Impatiens).

(9) Bristle contraction; hygroscopic bristles on the dispersule that promote movement with varying humidity.