Identifies the 28 trees and shrubs listed in the eighth-century legal tract Bretha comaithchesa, which are divided into four groups of seven: 1. airig fedo ‘nobles of the wood’: daur ‘oak’, coll ‘hazel’, cuilenn ‘holly’, ibar ‘yew’, uinnius ‘ash’, ochtach ‘Scots pine?', aball ‘wild apple-tree’; 2. aithig fedo ‘commoners of the wood’: fern ‘alder’, sail ‘willow’, scé ‘whitehorn, hawthorn’, cáerthann ‘rowan, mountain ash’, beithe ‘birch’, lem ‘elm’, idath ‘wild cherry?'; 3. fodla fedo ‘lower divisions of the wood’: draigen ‘blackthorn’, trom ‘elder, bore-tree’, féorus ‘spindle-tree’, findcholl ‘whitebeam?', caithne ‘arbutus, strawberry tree’, crithach ‘aspen’, crann fir ‘juniper?'; 4. losa fedo ‘bushes of the wood’: raith ‘bracken’, rait ‘bog-myrtle’, aiten ‘gorse, furze’, dris ‘bramble, blackberry’, fróech ‘heather’, gilcach ‘broom?', spín ‘wild rose?'. Also includes brief discussion of lecla and aín, variant names for ‘rushes’, and native trees and shrubs not included in the four classes.