This material is the threshed crop of (usually) winter-sown wheat. It is normally threshed by machine. The threshing process removes the grain and separates it from the straw. The straw is then tied in bundles by a trusser and delivered to the thatcher. Long straw requires more ground preparation than either of the two following materials. The straw is heaped, dampened and drawn before it is ready to be applied to the roof.
Unless they are subsequently sheared, long straw roofs exhibit a mixture of ears and butts on the surface and have a more shaggy (some say ‘poured on’) look than the other two kinds of material Eaves, gables and occasionally hips have external wooden fixings known variously as ‘liggers’, ‘runners’ or ‘rods’.

Roof being coated with Long Straw. Note ‘shaggy’ look to the thatch.

The same Long Straw roof showing finished look. The thatch has a flush wrapover ridge and lead flashings to the chimney.