Home›Sources›A Guide to OgamSourcesA Guide to OgamCitation FormatsGeneral ReferenceGeneral Reference Citation TextDivinity Atlas. "A Guide to Ogam." Accessed August 30, 2026. https://dev-divinity.interactiveatlas.org/sources/a-guide-to-ogam.Copy General ReferenceAPA StyleAPA Style Citation TextDivinity Atlas. (n.d.). A Guide to Ogam. Retrieved August 30, 2026, from https://dev-divinity.interactiveatlas.org/sources/a-guide-to-ogamCopy APA StyleBibTeXBibTeX Citation Text@misc{divinityatlas-a-guide-to-ogam, author = {Divinity Atlas}, title = {A Guide to Ogam}, year = {2026}, url = {https://dev-divinity.interactiveatlas.org/sources/a-guide-to-ogam}, note = {Accessed August 30, 2026} }Copy BibTeXDamian McManus's study works directly from the surviving ogham inscription corpus, and its central, checkable finding is that only a minority of the traditional tree names for the ogham letters are securely attested as arboreal at all, with the fuller tree alphabet now understood as a later scholastic elaboration added well after the script's original use. That specific corrective finding, reached by examining the inscriptions themselves rather than repeating the popular tree alphabet uncritically, is the book's real evidentiary contribution. Use it for the historical form of the ogham corpus and for what can and cannot be verified about the letter names' original meanings.FactsClaims Backed By This Source (887 claims)Comments (0)Reader Challenges (0 open reader challenges)FactsAssessmentReliability TierWell-attested1The standard scholarly treatment of the ogham corpus and its letter names, published in an academic monograph series, demonstrating that only a minority of the traditional letter names are securely tied to trees.NotesWell-attestedMaynooth Monographs 4. The standard scholarly treatment of the ogham corpus and of the letter names. McManus demonstrates that only a minority of the letter names are securely arboreal and treats the full tree alphabet as a later scholastic elaboration.CitationAuthorWell-attestedDamian McManusPublisherWell-attestedAn SagartPublication YearWell-attested1991URLWell-attestedhttps://archive.org/details/guidetoogam0000mcmaSource TypeWell-attestedacademic monographClaims Backed By This Source (887 claims)This source backs 887 claims across the atlas. As facts: 736 well-attested, 14 popular myth - corrected. As cited relationships: 54 holds, 15 connected. Plus 68 entities citing it as a general reference with no single fact or relationship attached.Disposition By TopicOgham Fews, 486 claims: 429 well-attested, 25 holds, 32 general references.Open Questions, 120 claims: 92 well-attested, 15 connected, 13 general references.Celtic Tree Signs, 93 claims: 68 well-attested, 12 popular myth - corrected, 13 general references.Articles, 78 claims: 78 well-attested.Aicmi (Ogham Groups), 50 claims: 36 well-attested, 9 holds, 5 general references.Disciplines, 25 claims: 4 well-attested, 2 popular myth - corrected, 18 holds, 1 general references.Categories, 18 claims: 16 well-attested, 2 general references.Languages, 9 claims: 5 well-attested, 2 holds, 2 general references.Sources, 8 claims: 8 well-attested.Well-attested736Aicmi (Ogham Groups)Aicme AilmeAicme BeitheAicme hUathaAicme MuineArticlesA Diphthong With No Letter of Its OwnA Fifth Group, Added After the Stone AlphabetA Language Known Only in StoneA Letter for a Sound Irish Did Not HaveA Letter Named for Its Own ShapeA Letter Named Horror, Later Assigned a HawthornA Loanword Rather Than a TreeAicme Ailme, the Fourth Family, and the Tree QuestionAicme Beithe, the First FamilyAicme HUatha, the Second FamilyAicme Muine, the Third FamilyAn alphabet of strokesCutting Ailm: One Notch Square Across the LineCutting Coll: Four Strokes in the Second FamilyCutting Dair: Two Strokes in the Second FamilyCutting Eadhadh: Four Notches in the Vowel FamilyCutting Fearn: Three Strokes, and a Sound That ChangedCutting Gort: Two Oblique StrokesCutting Iodhadh: Five Notches, and the End of the AlphabetCutting Luis: Two Strokes in the First FamilyCutting Muin: One Oblique Stroke Across the LineCutting NGetal: Three Oblique Strokes, and an Uncertain SoundCutting Nion: Five Strokes, and the End of a FamilyCutting Onn: Two Notches in the Vowel FamilyCutting Quert: Five Strokes, and a Lost DistinctionCutting Ruis: Five Oblique StrokesCutting Saille: Four Strokes in the First FamilyCutting Straif: Four Oblique StrokesCutting Tinne: Three Strokes in the Second FamilyCutting Uath: One Stroke, and a Sound Irish Did Not HaveCutting Ur: Three Notches in the Vowel FamilyHow the First Family Is CutHow the Fourth Family Is CutHow the Second Family Is CutHow the Third Family Is CutManuscript Letter, Not Monument LetterOgham and the God Who Supposedly Invented ItReading a Late Letter Without Overreading ItReed, Broom, or WoundingRobert Graves, and Where the Tree Calendar Came FromSulphur, Dye, and a Blackthorn Arriving LateThe Double X and Its Simplified Stand-InThe Earliest Irish Alphabet, Cut in StoneThe Ogham Letter AilmThe Ogham Letter Behind the Alder SignThe Ogham Letter Behind the Ash SignShowing 1 to 50 of 138 entities carrying this claim. NextPopular myth - corrected14Celtic Tree SignsAlder (Fearn)Ash (Nion)Birch (Beth)Hawthorn (Uath)Hazel (Coll)Holly (Tinne)Ivy (Gort)Oak (Duir)Reed (Ngetal)Rowan (Luis)Vine (Muin)Willow (Saille)DisciplinesOghamHolds54Aicmi (Ogham Groups)Aicme AilmeAicme BeitheAicme ForfedaAicme hUathaAicme MuineDisciplinesOghamLanguagesPrimitive IrishOgham FewsAilmBeithCollDairEabhadhEadhadhEmanchollFearnGortIfinIodhadhLuisMuinnGetalNionOnnOrQuertRuisSailleStraifTinneUathUilleannUrConnected15Open QuestionsDo Robert Graves's specific letter-to-month tree pairings in the 13-sign Celtic tree calendar correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of alder at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of ash at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of elder at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of hawthorn at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of hazel at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of holly at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of ivy at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of oak at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of reed at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of rowan at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of the vine at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of willow at this position, correspond to anything beyond his own argument in The White Goddess?General References68Aicmi (Ogham Groups)Aicme AilmeAicme BeitheAicme ForfedaAicme hUathaAicme MuineCategoriesAicmi (Ogham Groups)Ogham FewsCeltic Tree SignsAlder (Fearn)Ash (Nion)Birch (Beth)Elder (Ruis)Hawthorn (Uath)Hazel (Coll)Holly (Tinne)Ivy (Gort)Oak (Duir)Reed (Ngetal)Rowan (Luis)Vine (Muin)Willow (Saille)DisciplinesOghamLanguagesPrimitive IrishOgham FewsAilmBeithCollDairEabhadhEadhadhEmanchollFearnGortIfinIodhadhLuisMuinnGetalNionOnnOrQuertRuisSailleStraifTinneUathUilleannUrOpen QuestionsDo Robert Graves's specific letter-to-month tree pairings in the 13-sign Celtic tree calendar correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of alder at this position, correspond to anything beyond his own argument in The White Goddess?Do Robert Graves's tree pairings in the thirteen sign Celtic tree calendar, and the placing of ash at this position, correspond to anything beyond his own argument in The White Goddess?Showing 1 to 50 of 60 entities carrying this claim. NextComments (0)No comments yet. Be the first to share a thought.Sign in to join the discussion.Reader Challenges (0 open reader challenges)No disputes yet. Spotted an error or a better source? Open the first one.Sign in to dispute this or suggest a correction.View At A Past YearThe atlas records no dated fact of its own for this entry, so there is no other year to choose.Show This Year