▁Are oles ▁can ▁be ▁angular ▁to ▁round , ▁sometimes ▁forming ▁lo bes . ▁They ▁can ▁be ▁cont igu ous ▁or ▁scattered . ▁Color ▁is ▁variable ▁- ▁ble ached ▁white , ▁green - yellow , ▁and ▁other ▁had es ▁of ▁yellow . ▁It ▁has ▁a ▁lower ▁surface ▁when ▁squ am ul ose , ▁but ▁without ▁a ▁lower ▁cor tex . ▁With ▁age , ▁it ▁forms ▁st ipes . ▁Each ▁squ am ule ▁has ▁ 0 ▁or ▁one ▁ 1   mm ▁round ▁to ▁angular ▁ap othe cia ▁imm ers ed ▁in ▁it , ▁outside ▁desert ▁habit ats , ▁but ▁may ▁have ▁ 2 ▁to ▁ 1 0 ▁per ▁in ▁desert s . ▁Two ▁ap othe cia ▁may ▁merged ▁leaving ▁a ▁pen ins ula ▁( um bo ) ▁of ▁th all ine ▁t issue ▁through ▁the ▁disc . ▁Ap othe cia ▁may ▁have ▁le can or ine ▁marg ins . ▁Ap othe cia ▁have ▁a ▁flat ▁to ▁con ca ve ▁mostly ▁brown ▁or ▁re dd ish ▁brown , ▁con ca ve ▁disc . ▁ ▁L ichen ▁spot ▁tests ▁are ▁all ▁negative . ▁It ▁is ▁U V + ▁orange . ▁Second ary ▁met abol ites ▁include ▁rh iz oc arp ic ▁acid , ▁and ▁sometimes ▁trace ▁amounts ▁of ▁e pan or in . ▁ ▁When ▁young , ▁it ▁is ▁very ▁similar ▁to ▁Acc ar os por a ▁cont igua . ▁But ▁A . ▁social is ▁has ▁are olas ▁that ▁become ▁lo bed ▁and ▁squ am ul ose . ▁When ▁appearing ▁on ▁soil , ▁it ▁may ▁be