Which wood to burn?

Ferdiad, or 'man of smoke, Fergus's fire-servant, as in Iubdan's presence he kindled a fire, threw upon it a woodbine that twined round a tree, together with somewhat of all other kinds of timber, and this led Iubdan to say, 'Burn not the king of trees, for he ought not to be burnt; and wouldst thou, Ferdiad, but act by my counsel, then neither by sea nor by land shouldst thou ever be in danger.' Here he sang a lay:

O man that for Fergus of the feasts dost kindle fire, whether afloat or ashore never burn the king of woods. Monarch of Inis Fail's forests the woodbine is, whom none may hold captive; no feeble sovereign's effort is it to hug all tough trees in his embrace. The pliant woodbine if thou burn, wailings for misfortune will abound; dire extremity at weapons' points or drowning in great waves will come after. Burn not the precious appletree of spreading and low-sweeping bough: tree ever decked in bloom of white, against whose fair head all men put forth the hand. The surly blackthorn is a wanderer, and a wood that the artificer burns not; throughout his body, though it be scanty, birds in their flocks warble. The noble willow burn not, a tree sacred to poems; within his bloom bees are a-sucking, all love the little cage. The graceful tree with the berries, the wizards' tree, the rowan, burn; but spare the limber tree: burn not the slender hazel. Dark is the color of the ash: timber that makes the wheels to go; rods he furnishes for horsemen's hands, and his form turns battle into flight. Tenterhook among woods the spiteful briar is, by all means burn him that is so keen and green; he cuts, he flays the foot, and him that would advance he forcibly drags backward. Fiercest heat-giver of all timber is green oak, from him none may escape unhurt; by partiality for him the head is set on aching and by his acrid embers the eye is made sore. Alder, very battle-witch of all woods, tree that is hottest in the fight undoubtingly burn at thy discretion both the alder and the whitethorn. Holly, burn it green; holly, burn it dry; of all trees whatsoever the best is holly. Elder that hath tough bark, tree that in truth hurts sore: him that furnishes horses to the armies from the fairy-mound burn so that he be charred. The birch as well, if he be laid low, promises abiding fortune. Burn up most sure­ly and certainly the stalks that bear the constant pods. Suffer, if it so please thee, the russet aspen to come headlong down; burn, be it late or early, the tree with the trembling branch. Patriarch of long-lasting woods is the yew, sacred to feasts as is well known: of him now build dark-red vats of goodly size.

From: The Death of Fergus mac Leide