Juraian Treeships are spaceships that come from the planet Jurai.
In the OVA, the ships of the Juraian royal family were treeships (the ships housed trees which were the cores of the ship and are descendad from the Chousin Tsunami). They are sapient and have the ability to generate Light Hawk Wings which are the ultimate defense seen in the series.
There is no standard design or layout for these ships, as they are shaped by their own personalities and the personality of the one they are bonded to.
Although very powerful, later generations of Ouke-no-ki gradually became less powerful as they progress from Tsunami-no-ki. They also lose their 'Will' (that is, their minds and/or soul) if they are rooted on another planet. Funaho-no-ki was believed to be an example of this, but the tree did not lose its Will because of Washu's gems on the pommel end of Tenchi-ken, which provided the tree with power.
The treeships made a different appearance in Tenchi Universe. They did have a standard design (but were seperated into two different designs). They acted as more an actual fleet than all powerful god-like ships (due to the fact that in this continuity, they have no affiliation to Tsunami).