{{short description|Mushroom cap protuberance}}

[[image:Cantharellula umbonata 59168.jpg|thumb|right|''Cantharellula umbonata'' has an umbo.]] [[image:Psilocybe angulospora 14909.jpg|thumb|right|The cap of ''Psilocybe makarorae'' is acutely papillate.]]

An '''umbo''' is a raised area in the center of a mushroom cap. Caps that possess this feature are called ''umbonate''. Umbos that are sharply pointed are called ''acute'', while those that are more rounded are ''broadly umbonate''. If the umbo is elongated, it is ''cuspidate'', and if the umbo is sharply delineated but not elongated (somewhat resembling the shape of a human areola), it is called ''mammilate'' or ''papillate''.<ref name=Stuntz1978>{{cite book |vauthors=Stuntz DE, Largent DL, Thiers HD, Johnson DJ, Watling R |title=How to Identify Mushrooms to Genus I |publisher=Mad River Press |location=Eureka, California |year=1978 |pages=12–13 |isbn=978-0-916422-00-4}}</ref>

==References== {{reflist}}

Category:Fungal morphology and anatomy Category:Mycology