Pour la version
française
Updated
12-mars-2007
© CEFE -UMR 5175
Crepis sancta: a model system
Crepis sancta (Asteraceae) is a colonizing Mediterranean species largely spread in post cultural landscapes and in urban landscapes. This annual species germinates with fall rains and persists during winter in rosette leaf stage. The flowering period precociously occurs during the end of February and the pollination is done by generalist insects (especially Apis melifera in town). The mating system is largely outcrossing, with variable outcrossing rates (80-90% in countryside, 60-90% in town). This species, with a high dispersal potential, products two kinds of seed: small seeds with a pappus with high dispersal distance and large seeds deprived of pappus with a low dispersal distance.
 |
 |
 |
| flowers of Crepis sancta en fleur | Dispersal
seed with pappus |
No dispersal
seed without pappus (x 10) |
We study two kinds of populations: small fragmented urban population (rarely more than 40 individuals) in urban tree patches and large populations in the countryside or in urban parks.
 |
|
|
|
Small urban population |
Spatial structure of urban populations |
Continuous countryside populations |
|
Dpt DSE |
 |
 |
 |