For a fast germination you need to put this seeds in water and to clean the first black skin. Please see the picture with the brown seeds i done it my self.
Washingtonia Filifera is a palm native to the southern and southwestern USA states and northwest Mexico. This palm grows up to 23 m (exceptionally 30 m) in good growing conditions.
The leaves have a petiole up to 2 m long, bearing a fan of leaflets 1.5-2 m long, with white, thread-like fibers between the segments. When the leaves die they bend downwards and form a skirt around the trunk.
Washingtonia filifera can live from 80 to 250 years or more. They have been known to tolerate short-lived lows down to about -10°c.